Adhesion Strength Change Analysis Based on the Application Surface Area Ratio of Spot-Bonded Tiles on Vertical Walls of High Humidity Facilities

Round 1

Reviewer 1 Report

The authors have conducted the analysis of the adhesion strength as a function of the appliad area ratio on spot-bonded tiles. However, I have several major concerns that make me recommend the editor to reject the manuscript in the present form. Below I include some comments to improve the quality of the manuscript.

• For further reviewing, the line numbers should be included to facilitate the references to the reviewers.
• The author institutions should not be repeated.
• The written english must be substantially improved.
• Why the authors conducted an study focused on the influence of the surface area of spot-bonding of tiles when such tiles adhesion technique appears to be almost obsolete (according to the Inrtroduction)?
• The quality of the pictures should be substantially improved.
• Section 2.2.3 must be discussed, because tables and graphs can only help to support the authors comments, since they are not enough to complete a section. I would suggest the authors to discuss this whole section instead of merely showing a table. Indeed, the whole section 2.2 should consist of the spot-bonding and troweled adhesion techniques.
• There are uncountable typo errors (if the authors had included the line numbers I could indicate some of them). I suggest them carefully check the manuscript.
• Once again, all the information related to table 3 should somehow be included in the body of the text.
• The experimental scope is required to be included at the end of the manuscript’s introduction, since that section is intended to provide the necessary background to understand the manuscript, but also to justify the study conducted in it.
• There are some points within the text that lacks the number of the references. Please check all citations throughout the body of the text.
• Section 3.2.1. How did the authors estimated (or calculate, if possible) the pressing force to install the tile, the load and time exerted by the worker and the average working load? Is it the assessment establish in the following paragraph? The analysis applied over only 4 elements appears to be a bit inadequate, as in the case of such high variable conditions a greater population study is required. Moreover, personally I do not understand the reason why the authors chose the specimens’ manufacturing conditions (7 s, 100 N weight oon top of the tile), when both of those parameters did not fall within the ranges resulting from the previous study.
• The experimental section and the results should be separatedly presented.
• In table 4 what are the specimens? Replicates or different positions through the tile? And the No1-No5? Also replicates? It is not well indicated.
• In Figure 6, what is a) plotting? Adhesion strength versus what? Moreover, the linear fitting does not make any sense.
• Through this adhesion test, what do the authors think about using another adhesive to perform the test? If the change the epoxy adhesive, would the values change? Are they strictily analysing the cemetitious adhesive or the epoxy material? Why do not they consider to apply any other type of test?
• In section, depending on the percentage of tile are occupied with the cementitious ad and hesive, the amount of the adhesive (or the thickness) should differ from system to sytem (60, 80 and 100 %). That should be included.
• In section 4.1 the first paragraph could be omited, since it is only describing the location of the adhesive (what is obvious in spot-bonding method). For the same reason, most of the data collected in table 5 can also be omited.
• On the other hand, taking into account the tables and graphs contained in this manuscript (19 and 28), they are excessive, especially considering that most of them might be omitted.
• In general, the main concern regarding this study is that, the main conclusion that can be drawn was that the higher adhesion area, the higher adhesion strength, and to achieve that conclusion it is not required to conduct such research. Moreover, although from the very beginning of the introduction the authors highlighted the obsolescence of spot-bonding technique, they report that to achieve a proper adhesion strength it is required an AR higher than 80% (taking into consideration that they only analysed an AR=100%, above that “critical value”).

Author Response

Reviewer 1

We the authors would like to extend our greeting and sincere thanks to the reviewer for taking time out of their busy schedules to review and comment on our article manuscript. Due to your thorough examination of our paper, we believe we were able to make substantial improvement to the contents. Please refer to the below sections for our response to your individual comments and points of revision. Also please keep in mind that some of our responses may repeat as the points of revision and comment overlap with one another and our intended objectives, and as such we reorganized a few of the comments and responded to them accordingly.

The authors have conducted the analysis of the adhesion strength as a function of the appliad area ratio on spot-bonded tiles. However, I have several major concerns that make me recommend the editor to reject the manuscript in the present form. Below I include some comments to improve the quality of the manuscript.

Comment 1:

For further reviewing, the line numbers should be included to facilitate the references to the reviewers.

 

Response 1:

Line numbers have been added to the revised manuscript.

Comment 2

There are some points within the text that lacks the number of the references. Please check all citations throughout the body of the text.

 

Response 2:

Missing citations and reference numbers have been added (Line 165)

 

Comment 3:

The author institutions should not be repeated.

 

Response 3:

Repeated institution has been removed

 

Comment 4:

The written english must be substantially improved.

 

Response 5:

Manuscript has been revised to improve the language

 

Comment 6:

Why the authors conducted an study focused on the influence of the surface area of spot-bonding of tiles when such tiles adhesion technique appears to be almost obsolete (according to the Introduction)?

In general, the main concern regarding this study is that, the main conclusion that can be drawn was that the higher adhesion area, the higher adhesion strength, and to achieve that conclusion it is not required to conduct such research. Moreover, although from the very beginning of the introduction the authors highlighted the obsolescence of spot-bonding technique, they report that to achieve a proper adhesion strength it is required an AR higher than 80% (taking into consideration that they only analysed an AR=100%, above that “critical value”).

 

Response 6.

The background of the article has been revised to better articulate the purpose of this paper.

Spot-bonding method is mostly obsolete only in developed Countries such as Europe and U.S. (even in the U.S., this is debatable as spot-bonding methods can still be found in recent cases), and in other countries where construction quality regulations are more lax, spot-bonding is still practiced mostly in facilities where high humidity is expected (such as bathrooms and kitchens). This is because high quality plasters or polymerized adhesives are sensitive to humidity and will affect the adhesion quality of porcelain based tiles (both of which are usually higher in costs), where as ceramic tiles with usually higher absorptivity than porcelain tiles will be more easier to install using cement based adhesives (which are far cheaper and lower in quality than the former types). While this itself is not a critical problem, a couple of key issues are distinctly different between developed and un-developed countries, which is that 1) contractors use this excuse to push for continued usage of cheaper materials to reduce construction costs, 2) depending on the types of structures, larger and heavier tiles maybe used, which means more cementitious adhesive must be used. Constructors will need to be holding the tile while applying the cementitious adhesive onto the tile, making it heavier and more difficult for workers to apply them securely onto walls, thus to make work easier, workers only apply few globs of adhesive before installation, resulting in poor quality finishing. Furthermore, particularly in the cases of China and Korea, the workers are elderly, which results in even poorer quality than expected.

This is an issue that is very relevant and common for Asia (cases are also found for South East Asia and India), but rarely academically documented or made public for economic reasons (an absence in a proper standard for spot-bonding makes this even more problematic). It is quite evident that this practice will not be made completely discontinued any time soon, as the economic advantages of spot-bonding for contractors is too high. If such is the case, what should in the very least happen is that a study should be conducted to illustrate what the exact risks of poorly conducted spot-bonding tile installation is, and experimentally prove and demonstrate that if spot-bonding is to be used, then few glob application should not be continued, and this is the underlying purpose of this study. This point has been made more clear in the introduction (Lines), theoretical background (Lines) and conclusion of the revised paper.        

 

Comment 7

Section 2.2.3 must be discussed, because tables and graphs can only help to support the authors comments, since they are not enough to complete a section. I would suggest the authors to discuss this whole section instead of merely showing a table. Indeed, the whole section 2.2 should consist of the spot-bonding and troweled adhesion techniques. Once again, all the information related to table 3 should somehow be included in the body of the text.

Response 7

Subsections (2.2.1 ~ 2.2.3) have been removed and Section 2.2 has been revised such that Table 2 is better explained in the body text (Lines 97~105, 114~120, and 127~128)

 

Comment 8

The quality of the pictures should be substantially improved.

Response 8

Images have been replaced with more higher quality and more detailed illustrations (Figures in Table 2, Figure 4, 5, 7 and 9 along with adjustments to graphs and tables). The figure numbering have changed as well due to inclusion of new figures. Please refer to the revised manuscript for details.

 

Comment 9

There are uncountable typo errors (if the authors had included the line numbers I could indicate some of them). I suggest them carefully check the manuscript.

Response 9

Manuscript has been thoroughly checked for spelling and grammatical errors.

 

Comment 10

The experimental scope is required to be included at the end of the manuscript’s introduction, since that section is intended to provide the necessary background to understand the manuscript, but also to justify the study conducted in it.

 

Response 10

A brief explanation (and purpose) of the experimental scope has been included in the introduction section. Please refer to the revised version of the manuscript, Lines 63~76 for details.

 

Comment 11

The experimental section and the results should be separatedly presented.

 

Response 11

Sections have been rearranged such that the experimental method, and experimental analysis are separately presented

 

Comment 12

In section, depending on the percentage of tile are occupied with the cementitious adhesive, the amount of the adhesive (or the thickness) should differ from system to system (60, 80 and 100 %). That should be included.

Response 12

This has been made more clear in Lines 264~265

 

Comment 13

In section 4.1 the first paragraph could be omited, since it is only describing the location of the adhesive (what is obvious in spot-bonding method). For the same reason, most of the data collected in table 5 can also be omited.

 

Response 13

First Paragraph of Section 4.1 was omitted, but Table 5 contains core underlying principle of the intended goal of this paper, in that AR of 60 or 80% will not contribute to high dispersion of adhesive throughout the negative-side surface of the tile, and even 100% AR only reaches about 77.5% adhesion ratio on average. This is an important point as workers or contractors are using spot-bonding with few application of globs, mostly only on the corner sections of the tiles. The assumption follows that pressing the tiles will spread the adhesive, resulting in evenly distributed adhesive throughout the negative-side of the tile, but the results in Table 5  (Now Table 6 in the revised manuscript) shows that the adhesive distribution is far less than intended, and the mapped out tiles with secure adhesion and measurable adhesion strength is an indication of the risks of using only globs of adhesive for spot-bonding method. This point has been better illustrated in Lines 333~338.

 

Comment 14

Section 3.2.1. How did the authors estimated (or calculate, if possible) the pressing force to install the tile, the load and time exerted by the worker and the average working load? Is it the assessment establish in the following paragraph? The analysis applied over only 4 elements appears to be a bit inadequate, as in the case of such high variable conditions a greater population study is required. Moreover, personally I do not understand the reason why the authors chose the specimens’ manufacturing conditions (7 s, 100 N weight oon top of the tile), when both of those parameters did not fall within the ranges resulting from the previous study.

Response 14

A new table has been added to better illustrate in detail the results and methodology of the test and results. It must be kept in mind that for replicability of evaluation in future, results will vary as the above testing will need to be reconducted in accordance to different national standards or circumstances, and while greater population study is indeed required for a more accurate and reliable data, it should suffice to illustrate the intended goal for the demonstration of this evaluation in the study.

 

Comment 15

In table 4 what are the specimens? Replicates or different positions through the tile? And the No1-No5? Also replicates? It is not well indicated.

Response 15

Please refer to the revised sections and Lines 225 to 228 for explanation.

 

Comment 16

In Figure 6, what is a) plotting? Adhesion strength versus what? Moreover, the linear fitting does not make any sense.

Response 16

As is mentioned, Figure 6 a) was confusing and did not contribute much to the purpose of the intended meaning of the section, so it was removed, and detailed explanation of Figure 6 was included.

 

Comment 17

Through this adhesion test, what do the authors think about using another adhesive to perform the test? If the change the epoxy adhesive, would the values change? Are they strictily analysing the cemetitious adhesive or the epoxy material? Why do not they consider to apply any other type of test?

Response 17

Details for this has been taken into account in lines 148 to 160 in the revised manuscript. As this experimental methodology’s principle purpose is to compare the changing adhesion strength stability of the entire tile surface area based on the amount of adhesive used, common factors for causing adhesion failure such as filling rate (adhesion area), adhesive material type, water absorption rate, construction environment (temperature, humidity, etc.), structural deformation movement were made as consistent and simple as possible for this demonstration, and the scope of the experiment of this study was limited to the effect of the adhesion area using one type of cementitious adhesive and ceramic tile in compliance to the KS L 1001:2020 standard. Conclusion and results have been revised to better reflect on the need for continued investigation with different types of tiles, materials, pressure conditions, and ambient conditions as well.  

 

Comment 18

On the other hand, taking into account the tables and graphs contained in this manuscript (19 and 28), they are excessive, especially considering that most of them might be omitted.

Response 18

Experimental analysis and results section has been revised to better summarize the results and has been made more succinct by combining or omitting the relevant graphs and tables.

 

We the authors hope that the revisions made in this version of the draft is satisfactory to the reviewer. The authors would like to thank the reviewers once again for their time and effort towards the contribution to this manuscript.

Reviewer 2 Report

please see the attachment.

Comments for author File: Comments.pdf

Author Response

We the authors would like to extend our greeting and sincere thanks to the reviewer for taking time out of their busy schedules to review and comment on our article manuscript. Due to your thorough examination of our paper, we believe we were able to make substantial improvement to the contents. Please refer to the below sections for our response to your individual comments and points of revision. Also please keep in mind that some of our responses may repeat as the points of revision and comment overlap with one another and our intended objectives, and as such we reorganized a few of the comments and responded to them accordingly.

Comment 1

Electronic accesses are missing.

Response 1

Electronic Accesses have been included in the references section where applicable

Comment 2

The results are not novel and are as expected.

Response 2

The background of the article has been revised to better articulate the purpose of this paper. The intended goals and purpose of this paper and experimental study in the following comments’ responses

Comment 3

The evaluator does not understand why the word fracture is among the key words.

Response 3

Keywords has been revised (the word “fracture” has been removed)

Comment 4

The introduction overlooks many aspects that justify both the appropriate use of the spot-bonding procedure or the trowelled adhesion procedure: surface quality, type of tile and type of adhesive mortar. There seems to be a direct relationship between bonding surface and long-term bonding. This aspect depends, in humid rooms, strongly on the grouting material between pieces. This aspect is reflected in table 1. This table presents inaccuracies that must be clarified. Both in the USA and in Europe the mortars used are mixed of cement and polymer, and in some cases only polymer. It is not clear if in Asia they are only made of cement and sand.

Response 4

Details for this has been taken into account in lines 148 to 160 in the revised manuscript. As this experimental methodology’s principle purpose is to compare the changing adhesion strength stability of the entire tile surface area based on the amount of adhesive used, common factors for causing adhesion failure such as filling rate (adhesion area), adhesive material type, water absorption rate, construction environment (temperature, humidity, etc.), structural deformation movement were made as consistent and simple as possible for this demonstration, and the scope of the experiment of this study was limited to the effect of the adhesion area using one type of cementitious adhesive and ceramic tile in compliance to the KS L 1001:2020 standard. 

Also, a brief explanation (and purpose) of the experimental scope has been included in the introduction section. Please refer to the revised version of the manuscript, Lines 63~76 for details. Also, with regards to the relation ship with bonding surface and long-term bonding, this has not been reflected in the current state of the experimental regime. The purpose of the paper is to experimentally analyze the applicability of spot-bonding tile application method

Comment 5

Table 2 provides some confusing images. They present inscriptions that are in Korean and it would be preferable if they were in English. Also, in my opinion the images are permuted and do not correspond to the captions. They are very schematic images and they can lead to confusion: it does not consider the possibility of double gluing or the possibility that the mortar is deposited on the wall first and then the tile is pressed.

Response 5

Figure in Table 2 have been revised with better labels.

Comment 6

Neither the apparatus nor the applied pull-off regulations are described, nor the type of break obtained.

Response 6

Details of the apparatus has been included in Lines 212~213. As the regulations of the test method comply to the ISO 13007-2 methodology, the testing was conducted such that the breakage (pull-off) point criteria comply to the standard.

Comment 7

In figure 6a it is not understood which values are represented on the horizontal axis of the abscissa.

In figure 6b the color code of each specimen is not represented. Explanatory comments are lacking for the more than notable variations that are presented.

Response 7

As is mentioned, Figure 6 a) was confusing and did not contribute much to the purpose of the intended meaning of the section, so it was removed, and detailed explanation of Figure 6 was included.

 

Detailed explanation of Figure 6 was included (the location numbers (where light blue (1) and purple (4) are on the edges, and orange (2) and gray (3) are the in the center sections) in lines 226~229.

Comment 8

Figure 7 deserves some qualitative comment on the visual failure patterns. It is essential to identify the biker used in detail: composition, dosage and water cement ratio.

Response 8

For this, a detailed explanation has been added via a comparison of an another attempt of a different evaluation method. Please refer to the revised version of the manuscript, Lines 242~265 and Figure 9 (new) for details

Comment 9

In figures 11, 12 and 13 it is difficult to interpret which parameter is the adhesion factor.

Response 9

The adhesion factor element was deemed no longer required, as the percentage of the tiles with secure adhesion (with actually measurable adhesion strength) is the relevant data, so the parameter has been removed from the figures.

Comment 10

The application of the mortar forming 3, 4 or 5 strips must be indicated if it is in the short or long direction of the rectangular ceramic piece.

Response 10

This has been explained in Lines 272 to 273

Comment 11

Figures 18, 22 and 26 deserve a text where they are compared. In all of them, the number of values that exceed the minimum resistance is surprising.

Response 11

Figure 18, 22 and 26 were combined into one (Now Figure 17), and explanation has been included in Lines 411 to 424

 

METHODOLOGY

Comment 1

The process of sectioning the tile into 40 portions is not explained in sufficient detail. It is foreseeable that the cutting process significantly alters the final bond strength because it introduces large dynamic stresses in a short period of time. The authors must say something about it.

Response 1

This section and the logic for sectioning the tile into 40 pieces was explained more in detail in Lines 266~273 in the revised manuscript. As shown in Figure 10, a 250✕400mm ceramic tile (compliant to the specifications in Table 3) designed for the new evaluation was used and the entire surface of the tile was sectioned into size of 50✕50 mm pieces (total of 40 pieces), where into 8 pieces were lined up along the width and 5 pieces along the length of the tile. This process was deemed necessary for the evaluation to be able to 1) objectively and completely compare and assess the degree of adhesive dispersion ratio after pressing between the specimens of different ARs (to be able to determine how many pieces would end up with results similar to the one found in Figure 8, number 4 tile piece), and 2) the sectioned pieces are in accord with the specifications of the ISO evaluation standard. The process was repeated for tiles where the cementitious adhesive application surface ratio differed by the following intervals; 60±2%, 80±2%, and 100% surfaces area.

Comment 2

The characteristics of the tile are unknown, especially its firing, porosity, etc.

Response 2

Characteristics of the tile are in compliance to the tile specifications outlines in ISO 10545-2 and ISO 13007-2 and is illustrated in Table 3. And the Firing temperature characteristic has been included

Comment 3

The value of 13.2% seems wrong or exaggerated.

Response 3

The absorptivity value is that of a ceramic tile, and according to the Korean regulation standard (KS L 1001:2020), tiles used for indoor construction, as long as it is under 18% it is within the allowed range. As noted by the reviewer, this is a fundamental problem that allows the usage of inexpensive and lower quality tile materials (in the case of Korea, and similar situations can be found in other under developed nations).  This is because high quality plasters or polymerized adhesives are sensitive to humidity and will affect the adhesion quality of porcelain based tiles (both of which are usually higher in costs), where as ceramic tiles with usually higher absorptivity than porcelain tiles will be more easier to install using cement based adhesives (which are far cheaper and lower in quality than the former types). While this itself is not a critical problem, a couple of key issues are distinctly different between developed and un-developed countries, which is that 1) contractors use this excuse to push for continued usage of cheaper materials to reduce construction costs, 2) depending on the types of structures, larger and heavier tiles maybe used, which means more cementitious adhesive must be used. Constructors will need to be holding the tile while applying the cementitious adhesive onto the tile, making it heavier and more difficult for workers to apply them securely onto walls, thus to make work easier, workers only apply few globs of adhesive before installation, resulting in poor quality finishing. Furthermore, particularly in the cases of China and Korea, the workers are elderly, which results in even poorer quality than expected.

Comment 4

The debate on pressure is very interesting but it sticks to the vertical case while the experimental campaign is carried out with horizontally placed tiles. It is a pity that this section is abandoned in the later experimental campaign.

Response 4

A new table has been added to better illustrate in detail the results and methodology of the test and results. It must be kept in mind that for replicability of evaluation in future, results will vary as the above testing will need to be reconducted in accordance to different national standards or circumstances, and while greater population study is indeed required for a more accurate and reliable data, it should suffice to illustrate the intended goal for the demonstration of this evaluation in the study.

Comment 5

Table 4 is very interesting and it would also deserve to present the average value of each of the horizontal lines or rows. There is a fundamental inconsistency that should be justified: a very specific European standard is used to evaluate an Asian procedure. This may detract from some conclusions.

Response 5

Table 4 contains core underlying principle of the intended goal of this paper, in that AR of 60 or 80% will not contribute to high dispersion of adhesive throughout the negative-side surface of the tile, and even 100% AR only reaches about 77.5% adhesion ratio on average. This is an important point as workers or contractors are using spot-bonding with few application of globs, mostly only on the corner sections of the tiles. The assumption follows that pressing the tiles will spread the adhesive, resulting in evenly distributed adhesive throughout the negative-side of the tile, but the results show that the adhesive distribution is far less than intended, and the mapped out tiles with secure adhesion and measurable adhesion strength is an indication of the risks of using only globs of adhesive for spot-bonding method. This point has been better illustrated in Lines 333~338.

 

We the authors hope that the revisions made in this version of the draft is satisfactory to the reviewer. The authors would like to thank the reviewers once again for their time and effort towards the contribution to this manuscript.

Reviewer 3 Report

The authors described an experimental test method for evaluating the effective bonding area of tiles as a wall covering. The research compares two bonding methodologies, and aims to improve the test standard. The tests are still affected by the uncertainty of the different manpower that installs the tile, and although they have been explained in an exhaustive way, it is believed that this experimental research addresses the resolution of a marginal problem in the construction of a building work. The authors have introduced several external causes that can affect the durability of the bond, for example humidity (very present in the bathroom). How can tests take this variable into account, for example? The research could also extend to bonding problems involving larger tiles on building facades, where the area and method of bonding the mortar are more important and interesting variables. Furthermore, all citations in the bibliography are without the name of the authors, and must be integrated according to the journal template. The paper and the research should be expanded towards bonding problems on a larger scale than the simple bathroom tile, such as to justify an experimentation and an ad hoc evaluation methodology. It is advisable to direct the paper to technical architecture magazines.

Author Response

We the authors would like to extend our greeting and sincere thanks to the reviewer for taking time out of their busy schedules to review and comment on our article manuscript. Due to your thorough examination of our paper, we believe we were able to make substantial improvement to the contents. Please refer to the below sections for our response to your individual comments and points of revision. Also please keep in mind that some of our responses may repeat as the points of revision and comment overlap with one another and our intended objectives, and as such we reorganized a few of the comments and responded to them accordingly.

Comment 1

The research compares two bonding methodologies, and aims to improve the test standard. The tests are still affected by the uncertainty of the different manpower that installs the tile, and although they have been explained in an exhaustive way, it is believed that this experimental research addresses the resolution of a marginal problem in the construction of a building work. How can tests take this variable into account, for example? The research could also extend to bonding problems involving larger tiles on building facades, where the area and method of bonding the mortar are more important and interesting variables.

Response 1

The background of the article has been revised to better articulate the purpose of this paper.

Spot-bonding method is mostly obsolete only in developed Countries such as Europe and U.S. (even in the U.S., this is debatable as spot-bonding methods can still be found in recent cases), and in other countries where construction quality regulations are more lax, spot-bonding is still practiced mostly in facilities where high humidity is expected (such as bathrooms and kitchens). This is because high quality plasters or polymerized adhesives are sensitive to humidity and will affect the adhesion quality of porcelain based tiles (both of which are usually higher in costs), where as ceramic tiles with usually higher absorptivity than porcelain tiles will be more easier to install using cement based adhesives (which are far cheaper and lower in quality than the former types). While this itself is not a critical problem, a couple of key issues are distinctly different between developed and un-developed countries, which is that 1) contractors use this excuse to push for continued usage of cheaper materials to reduce construction costs, 2) depending on the types of structures, larger and heavier tiles maybe used, which means more cementitious adhesive must be used. Constructors will need to be holding the tile while applying the cementitious adhesive onto the tile, making it heavier and more difficult for workers to apply them securely onto walls, thus to make work easier, workers only apply few globs of adhesive before installation, resulting in poor quality finishing. Furthermore, particularly in the cases of China and Korea, the workers are elderly, which results in even poorer quality than expected.

This is an issue that is very relevant and common for Asia (cases are also found for South East Asia and India), but rarely academically documented or made public for economic reasons (an absence in a proper standard for spot-bonding makes this even more problematic). It is quite evident that this practice will not be made completely discontinued any time soon, as the economic advantages of spot-bonding for contractors is too high. If such is the case, what should in the very least happen is that a study should be conducted to illustrate what the exact risks of poorly conducted spot-bonding tile installation is, and experimentally prove and demonstrate that if spot-bonding is to be used, then few glob application should not be continued, and this is the underlying purpose of this study. This point has been made more clear in the introduction (Lines), theoretical background (Lines) and conclusion of the revised paper.       

The paper and the research should be expanded towards bonding problems on a larger scale than the simple bathroom tile, such as to justify an experimentation and an ad hoc evaluation methodology.

It is not the intention to provide a large scale resolution through this research and the results yet, as the social and economic issues purportedly challenged by this study is a sensitive topic in some countries, yet it is still very required. Our intent for the time being is to introduce the concept of resolving the issues related to spot-bonding methods by highlighting key issues (glob-application and material selection) by first introducing a methodology that evaluates the adhesive dispersion (in this case, the lack in thereof with glob-applied specimens) by thorough and individualistic examination as is demonstrated in this study. As contractors that still persist in using low quality form, in both technique and material, of spot-bonding insist that spot-bonding is still viable, an execution/demonstration of this new evaluation method in an academic paper and documented experimental results is hoped to be a starting stage towards what the reviewer suggests with this comment.

Comment 3

Furthermore, all citations in the bibliography are without the name of the authors, and must be integrated according to the journal template.

Response 3

Citations have been revised

 

We the authors hope that the revisions made in this version of the draft is satisfactory to the reviewer. The authors would like to thank the reviewers once again for their time and effort towards the contribution to this manuscript.

Round 2

Reviewer 1 Report

Although the authors have improved the quality of the manuscript (I can see the work behind this manuscript), the reduced scientific soundness of this study in the present form makes me to suggest its rejection.

Comments for author File: Comments.pdf

Reviewer 3 Report

The authors have implemented the paper with the requests for clarification and insights required. The paper is improved in focus and explanation of scientific results and therefore deserves publication.