Evaluation of Moisture Performance of Tall Wood Building Envelope under Climate Change in Different Canadian Climatic Regions
Round 1
Reviewer 1 Report
Dear Authors.
A very interesting simulation study of CLT in high-rise/tall buildings. This work is very extensive and covers very well the relevant input for performing hygrothermal simulations. It gives clear indications of the influence on moisture problems in buildings subjected to future climate compared to today's climate.
The paper is about the design of CLT structures. However, for tall building I see the construction phase as a huge risk of getting rain into the structures. This is not discussed, and the authors mention that 1% rain intrusion might be to high, however the moisture could also be trapped on the inside of the WRB during construction, if not a weather protection of the building is introduced. I think the moisture load during construction phase is at least a relevant to investigate, when considering the robustness of the CLT structures. That said, you can consider if it will be relevant to include this topic in your discussion.
I have only a few comments that I would like you to consider.
Comment to address:
L17: What is the difference between vented and ventilated. Perhaps you can bring the explanation in L356 earlier in the paper.
L114. The sheathing membrane should perhaps be explained a bit more in regards to it vapour diffusion resistance in relation to RH (it is described in Table 2). You evaluated on the risk of mould on the inside of the membrane, but it seems vapour tight and the moisture source is on the outside of the membrane. The membrane is important for the durability of the CLT structure. Would it be more beneficial to install an intelligent airtight membrane with varying diffusion resistance in regards to RH. I think this would be valuable to include in the paper.
L120. It is true that CLT is expected to be air/vapour tight, however, I think that the paper need to at least mention the issues of assemblies and CLT surfaces not covered by gypsum. Assemblies and penetration in not covered wall parts might not be air/vapour tight. This could influence the durability. This study focuses on the 1D wall part.
L123-130 / 140. Figure 1 can be improved by adding the interval of material thickness.
Figure 3. is very difficult to see the difference between blue and orange boxplots. Perhaps a short description in the caption that for each location the left boxplot is H, and the right is F.
Figure 5. Rainscreen should be changed to air cavity. Follow the terminology used in figure 1.
L308-311. The simulations are run for 3 years with same climate file for each run. Are you sure that the construction reaches stable conditions and not having e.g. an increase in moisture content? In figure 8 the MoI keeps increasing after 3 years, which indicates that the moisture content stabilized within the 3 years. As the discussion look at the changes in mould growth index, I would like the authors to consider the simulation period of 3 years in relation to the results.
L674-677. Was the air change varied? In the method you describe that it is a mean value. Here you discuss the vented and ventilated air changes. To make this part more clear, could you please rephrase that section. Perhaps include the used air changes (40-90) and (100-350), respectively.
L681. Please check the wording of 'wind driving en rain'.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper evaluates the moisture performance of tall wood building envelope under climate change in different Canadian climatic regions. The objective and scope are well defined. The study is presented in a logical and thorough way, and I find the result comprehensible presented.
My main concern is about your treatment of your second intent of the study. I don’t find it very focused within the paper. Hence, I recommend skipping «investigating the effects of selected hygrothermal parameters on the response of wall assemblies in order to provide a framework to develop risk mitigation solutions». You are not focusing on that in your discussions and in the end, you only point it out for further studies.
Some minor comments:
· There are several fatal errors in referring the literature. Defo et al. is not [7]. According to the list it is [14]. Chang et al. is [10], [11] or [13], not [6]. [1] and [2] seems to be correct. All the others might be wrong.
· 13 story tall wood building. You might shortly comment the loadbearing structure. 3-layer CLT is not sufficient loadbearing capacity.
· The resolution of Figure 1 is too low.
· Figure 5: Should legend â‘¡ be «drainage cavity»?
· The conclusion section is presented as a summary. The repeating text should be avoided. I recommend skipping the first paragraph.
Author Response
Please see attached file
Author Response File: Author Response.pdf
Reviewer 3 Report
In this paper, the effects of climate change on the moisture performance of cross-laminated timber wall assemblies used in tall wood buildings were investigated taking into account 12 different Canadian climatic regions.
It constitutes a very interesting topic deserving in depth-study and publication in the scientific literature. Detailed comments in the following:
- The authors have the same affiliation. Please keep a unique affiliation. For example: 1National Research Council Canada; [email protected] (M.D.); [email protected] (L.W.); ect.
- Please not use abbreviation in the keywords;
- Introduction: expand the bibliographic research with more recent works;
- In the text there are many abbreviations. Please add a Nomenclature section in order to easier read;
- The notes in Table 1 and Table 2 are too detailed. Comments should be moved into the text and leave only it is necessary in the notes;
- Figures and Tables should be cited in the text not in bold;
- Line 136: add the unit of measure after the last thermal resistance value (5.26);
- Line 136: add Table with considered thermal resistance and thickness values of the wall in function of climatic area;
- Figure 1: improve the resolution and add numbers of each layer both in the figure and in the legend
- Avoid white spaces before the text (see pag. 5 above 2.4 section; pag. 8 above 2.5 section; pag. 14 above Figure 8; pag. 14 under Figure 8; pag. 17 above Table 5; pag. 20 under Conflicts of Interest; pag. 21 above References;
- Figures 2, 3, 4, 5, 6, 7, 8 and 9: the captions should be resumed and more incisive. Comments should be moved into the text and leave only it is necessary in the captions;
- Figure 3, Figure 4, Figure 6, Figure 9 should be improved. They are hard to read and too small. Please improve and modify when necessary in order to easy read;
- Tables 4 and 5: make them more readable, for example by highlighting both significant positive and negative results;
- Conclusions: they should be more concise and report only the relevant conclusions of the work also as a bulleted list;
- References: there are 7 self-citations.
The English must also be improved with the help of a native speaker.
Author Response
Please see attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
AuAuthors have improved the quality of the manuscript. I agree to publish this paper.thors have improved the quality of the manuscript. I agree to publish this paper.
