Moisture Buffering and Mold Growth Characteristics of Naturally Ventilated Lime Plastered Houses.

Thank you for reviewing our article and giving your valuable comments to improve the shortcomings of our work. We have carried out a major revision of the article and also improved its language.  In the revised track mode document, the changes are highlighted in the green colour font. The corrections carried out in the manuscript as per the reviewers’ comments and the corresponding responses are detailed below:

Reviewer 1 Comments:

• An interesting study is presented that has combined modelling, lab experiments, and field work to better understand the relationship between lime plaster and mould. However, the report would benefit from a thorough proofread and some clarifications to improve readability. Providing further details on the method would help readers to better understand the input data used for analysis.
  • As per your suggestion, the authors have carried out a major revision of the paper and improved the language of the text.
• There are several text errors and formatting issues. For example, the Figure 25 caption says “Marchq”, and on page 7 it is stated “The above figure shows …” but the figure it is referring to is below the sentence. On page 22, there is paragraph text between figure 30 and its caption.
  • As pointed out correctly, the mentioned issues have been corrected in the revised manuscript.
• Language needs to be improved as some sentences do not make grammatical sense which makes understanding the author difficult. For example, the following sentence in Section 3.1 is not clear: "The materials binding, a room stores, and releases moisture.".
  • The authors have improved the language substantially and removed the repetitions in the text.

• Presentation could be improved by making language appear more consistent. For example, on pages 7-8 the term relative humidity is sometimes capitalised seemingly at random.
  • As suggested, the mentioned issues have been corrected in the revised manuscript.

• There are many statements where references should be added for support. For example, references are missing for the stated lifespan of lime mortar in Section 1, and for the claimed literary evidence regarding the composition of lime mortar in Section 1.1.
  • As per your suggestion, the link has been updated. Link for the paper: https://www.sciencedirect.com/science/article/abs/pii/S2352710217303625
  • The above is given on Page No: 1.
• Please could the aim of the study be clearly stated at the end of the Introduction.
  • As suggested, in the revised manuscript, the aim of the study is clearly mentioned in the last paragraph of page 2. The same can be seen in the track mode document in the green highlight on page 2.
• Please could differences between the original curve and derived curve in Figure 1 be clarified.
  • As suggested, the differences have been given in the revised manuscript and are given on page 6 as “The difference observed between the curves is very minuscule with a maximum difference of 0.002 µ(kg/kg).”
• Table 3-3-2 should specify the units of volume and how this was calculated i.e. from floor plans or measurements by experimenter.
  • As suggested, the units have been mentioned in the revised manuscript on page 5 and it is also mentioned that the volume is calculated from the measurements taken for floor plans. Click here to see the plans
• The model of the HOBO loggers should be specified in Section 3.3.
  • As pointed out, the above has been addressed and the model numbers for the loggers have been specified on page 4, page 6 and Table 1 on page 5
• Are the stabilised RHs from the salt solutions consistent with what is expected from literature? The values could be compared to another source e.g. Greenspan (1976).
  • Yes, the stabilised RHs from the salt solutions were consistent with those expected (from Quincot (2011)[1]  Page No: 6) Click here to access the raw data.
• Please could the weather files used for simulation be specified.
  • The weather files were taken from Energy Plus weather data.  (Ahmedabad weather data) and is mentioned in the revised manuscript on page 6
• In Section 4.1.1, it is stated that “… there is no external source of the moisture other than occupancy”. The modelling method should describe what moisture production profile was used for the case study model. For occupancy, this would be the occupancy hours and rate per hour. Would including other moisture sources (e.g. cooking) be important?
  • The occupancy number considered is as per observations on site for each individual case which is simulated for 24 hours of the day. The requested details are specified in the document. Page No: 8
• Please could you specify the number of spot measurements that were used in Section 4.2 to produce each figure (n=?).
  • The spot measurements sample is about 85-90 readings for each space during the study span (25^th of December 2019 to 16^th March 2020). This has been specified in the revised manuscript on the page No: 10
• Please could you clarify Figure 28. The x-axis is moisture content and y-axis is frequency, and the caption states the walls were studied from December to March. However, the figure specifies "December to May" and "Monsoon months" in boxes for different moisture content ranges and it is unclear why.
  • As suggested, the above has been addressed and Figure 28 is replaced with corrected Figure 18 on page 13 in the revised manuscript. The frequency indicates the number of occurrences of the same reading recorded during the multiple visits of the survey.
• For Figure 30, it appears as though some room characteristics were assessed (i.e. ventilation, sunlight, clutter). How these were assessed should be mentioned in the methods section. For example, what is the difference between ‘High’ clutter and ‘Moderate’ clutter? For each room, is this an observation based on a single site visit or multiple site visits? Also, whilst ventilation openings may be closed, there will still be air exchange due to infiltration which could be substantial if the building is not airtight. Is the interest in purpose-provided ventilation or overall air exchange?
  • Clutter is considered low, moderate and high if the furniture and other items are blocking the walls by 30%, 60% or 70%. This was based on just visual observations and surveys conducted during the multiple site visits.  The same is clarified in the revised manuscript on page 14.
  • The authors acknowledge the fact that there will be air exchange due to infiltration. However, the closed ventilation openings did not ensure that the humid air near the surfaces is replaced. It also prevented sunlight from entering the space. The interest in the purpose is of ‘provided ventilation’ and not overall air exchange. It is necessary that the stagnant air and moisture near the wall surface are removed by ventilation to avoid mould issues. Page No: 14
• Figure 31 is confusing. The "Mould observed" and "No Mold Observed" rings do not seem to correspond to the inner sections.
  • To avoid confusion the authors have removed this figure which essentially has the same data as in Figure 20 of the revised manuscript. The figure was for representation, reflecting the same data but in a different form to indicate the overall observations. Another reason to remove the figure is to limit the total number of figures
• The results section should be renamed as Results and Discussion, but I would recommend writing a separate Discussion section given the complexity of the topic.
  • As per your suggestions, the result section in the revised manuscript is titled “Results and Discussion”. The same is can be seen on page 7

Reviewer 2 Comments:

• Lime cycle and related explanations are unnecessary to give because there will be no correlation later in the study. 
  • As per your suggestion, the lime cycle explanation has been removed from the Introduction section on Page 1
• Long explanation of lime is not needed. I recommend to delete this part. 
  • As suggested, the unnecessary explanation on lime has been removed from in the revised manuscript.
• Please make the introduction concise and clear. Authors should avoid repetition. Authors should briefly explain why lime is favourable in a few sentences and what is lack in the field without repetition. The section should be named as Results and Discussion, if not where is the discussion?
  • As per your suggestion, the introduction has been wholly rewritten and shortened in the revised manuscript. Repetitions have also been removed. (Pages No: 1 to 2)
• How this life span is calculated in this reference? What about more than 2000 years old Roman mortars. reference is needed
  • As per your suggestion, a reference is added at the end of the sentence.  Link for the paper: https://www.sciencedirect.com/science/article/abs/pii/S2352710217303625 and is reflected on Page No: 1
• Methodology should be described briefly. It is estimated that the first study is modelling, the second study is an in-situ examination and the last study is experimental work. If it is correct, please explain it clearly. 
  • As suggested, the methodology section has been revised and the 3 parts of the study are mentioned on pages 3 to 7.
• Abbreviation should be defined clearly when it is used for the first time.
  • As per your suggestion, abbreviations are introduced in the text when they are used for the first time.
• Please indicate name of the equipment in a, b, c, d, and e in Figure 5.
  • As pointed out correctly, the equipment information is given in the revised manuscript on page 4 below Figure 3.
• Table 332 should go to results or appendices section. 
  • As per your suggestion, Table 332 is now given in the Appendix on page 21
• What is Language Lab? Why is it relevant? 
  • This has been edited. That literature study is mentioned because it has post-occupancy survey observations of lime plaster which provides a relevant base to the hypothesis of MRT modulations. The paper reference is there in the manuscript. The name Language Lab is removed, but the observations and reference still remain the same Page No: 1
• What does sulphate phase of the lime plaster mortar formation mean? Please revise. 
  • The above sentence has been removed in the revised manuscript on the page No: 1
• Which type of microscope is used should be defined in methods section. Figure 32. If it is an stereomicroscope (or not), the magnification should be defined for all images. Quality of the images should be improved. Polarized optical microscopy? scanning electron microscopy? section 4.2
  • Due to COVID restrictions, it was not possible to access or arrange a high-resolution microscope. The images were taken under a 40x simple microscope. The same is mentioned on Page No: 15
• Conclusions should be reflected by results. I recommend rewriting the manuscript with clear objectives and results therefore conclusions can be inferred better. 
  • As per your suggestion, the authors have tried to rewrite the manuscript with clear objectives and results.

[1] Quincot G, Azenha M, Barros J, et al. Use of salt solutions for assuring constant relative humidity conditions in contained environments. Found Sci Technol. 2011;33.

Lime plaster is well known for its moisture buffering capabilities but is also susceptible to mould growth. This work focusses on the hygrothermal performance of lime plaster in naturally ventilated residential spaces. Surveys are carried out for 45 traditional buildings of Ahmedabad in India with measurements of ambient variables, such as temperature, relative humidity, wall moisture content, etc. Mould growth patterns of these spaces are related to the measured variables and wall characteristics. Hygrothermal simulations of some spaces are also carried out to observe the moisture buffering of lime plaster. Experimental observations are contrasted with simulation results to see if numerical predictions are realistic.