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Post by lincoln on Nov 2, 2015 3:55:06 GMT -5
Hey MUF'ers, looking for some help insulating my steel garage, soon to be my home workshop. There are a LOT of products, and it gets confusing! The roof is sorted - I'll be using 'Foilboard', a 25mm lightweight insulating board, screwed to the underside of the timber roof battens, all joints taped. Should be straightforward. I'll be building stud walls for the interior, lined with 12mm melamine faced board. There will be an air gap between the stud wall and the external steel sheeting. Should I line the back of these internal walls with a 'building wrap', then insulate with batts? If I do, does the air gap need some sort of venting to prevent moisture, or is this step not necessary?( Our climate is fairly mild) Thanks for any advice, ideas.
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Post by wrightwoodwork on Nov 2, 2015 5:25:41 GMT -5
On the outside of the frame you want to put a breathable membrane like tyvek,klober. The foil ones are better as they reflect the outside temperature then the battens and the out side cladding. It basically works like a gortex jacket let moisture pas through from the inside yet not from the outside. I'm not sure in your part of the world we use weep holes to help get rid of any moisture from above windows and doors also along the bottom of sections. Then on the inside we use vapour control layer be it foil backed plasterboard or visqueen. A good website to look is siga, or cellotex.
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Post by holmz on Nov 2, 2015 6:00:54 GMT -5
Lincoln,
A friend just moved from Balmain to the UK and if headed to West Virginia. Been looking at some insulation with him.Aerogel is redicuoulsy expensive, but they make an aerogel tape that ust goes on the studs, and thermal imagaging shows that the studs carry the heat out. Ideally you have a wall where teh inside ddoes not connect to the outside, so pmaybe a bit like the accoustic wall I put up a few months ago. (Why they use Besser blocks here is a mystery) Really if it is a steel frame then you probably want to consider the aerogel tape, as the steel with telegraph the heat straight through. I am headed to the states over XMAS in case it makes a difference.
The other factor is thermal mass. ideally one can store and release the heat, but that relies on some infrastructure, which is usually water, or windows that let light in to heat a floor. Even an old second hand solar water heater would be good (or two or three), and then pump that though fold fashioned radiators shen you need heat. If it is sunny every few days it would poentionally work.
You start off with the R-factor for the roof and walls and the model the heat flow based upon the temp difference. Then you know how much heat needs to be added and at what rate throughout the day..
So ideally you could use a roof that lets heat and light in for warmth and insulates for the heat. I forget the product name, but I'll insert in later.
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Post by lincoln on Nov 2, 2015 6:41:33 GMT -5
Thanks for the input, appreciate it. I should have said that it's an existing garage, so getting a layer between the exterior cladding and steel frame isn't possible. The two main reasons for me insulating it are keeping heat out in summer, and keeping the noise of routers, saws etc from our house. I'm fairly confident that what I'm planning will work well enough for a shop, but I'm a bit concerned about moisture building up where I can't see it - ie. on the internal side of the cladding behind the partition stud walls.
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Post by holmz on Nov 2, 2015 8:06:35 GMT -5
How many meters of wall do you have? I used 2 sheets of gyprock, The first was fire rated and ~12 or 15-mm thick to the studs. The second was normal. I cut both with the MT55. Between teh two sheets I put Green Glue, and I still have a lot of it left. I think I used 4 tubes and they are the large size.
Most of the sound goes through the door is it has not found air gaps first. Those get closed off with dropping thresholds and attention to power points.
You could still do the aerogel tape on the inside if there is not allready sheeting over the studs,
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Post by jimbouk on Nov 2, 2015 9:42:43 GMT -5
Where the workshop adjoins the house I would put resilient bars on the stud first to help kill the vibrational noise. Put sound insulation behind, double board and seal all joins and gaps so you have a 'floating wall' this is the best you can do without going over the top!
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Post by rizzoa13 on Nov 2, 2015 10:58:13 GMT -5
I agree on building a second free standing wall. I'm doing something similiar in my basement. Metal stud set 24" OC filled with non faced insulation. You want the entire assembly to breath so trapping moisture behind that wall is a bad idea. You'd probably be better served using some type of air barrier on the inside behind your Sheetrock and definately not on the backside.
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Post by Red on Nov 2, 2015 11:30:05 GMT -5
Have you considered the use of EPS or XPS sheeting in your project, Lincoln? Although I don't understand the argument, some folks worry about off-gassing...but yours is a workshop project, so that shouldn't really be a concern.
We've been working with both a lot this year and it's really a great product for ease of use, insulation properties and sound-deadening. The XPS sheeting has the added bonus of being an inherent moisture barrier, as well.
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Post by toomanytoys on Nov 2, 2015 16:46:14 GMT -5
There's been some grumbling about XPS and other foam sheets. Some lab tests and reviews of installed products have shown over time the sheets shrink, with comments of 2% over the dimensions, 5/8" to 1 3/4" by some examples. There's also been concern over just using seam tape and not using Tyvex over the surface. With the dimensional movement the tape can loosen and hold water if not tear altogether. There's some info being out there by DuPont, I'll see if I can find a link to it. edit - Here's the link. www.dupont.com/content/dam/assets/products-and-services/construction-materials/assets/Architectural%20Binder/Weather%20Barriers%20A%20Must%20with%20Exterior%20Foam%20Sheathing%20K25107.pdfOf course dupont may be trying to do an upsell on Tyvex ..... But I've seen the shrinkage comments before, as well as the manufacturers saying the newest foam sheets have been reformulated to reduce the problem. I'm just not sure how many years it may take to confirm the aging issue.
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Post by lincoln on Nov 2, 2015 18:55:37 GMT -5
Thanks again, everyone. I know that I'm totally over thinking this, which is what I do when I'm not 100% sure of something.
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Post by Red on Nov 2, 2015 21:18:21 GMT -5
There's been some grumbling about XPS and other foam sheets. Some lab tests and reviews of installed products have shown over time the sheets shrink, with comments of 2% over the dimensions, 5/8" to 1 3/4" by some examples. There's also been concern over just using seam tape and not using Tyvex over the surface. With the dimensional movement the tape can loosen and hold water if not tear altogether. There's some info being out there by DuPont, I'll see if I can find a link to it. edit - Here's the link. www.dupont.com/content/dam/assets/products-and-services/construction-materials/assets/Architectural%20Binder/Weather%20Barriers%20A%20Must%20with%20Exterior%20Foam%20Sheathing%20K25107.pdfOf course dupont may be trying to do an upsell on Tyvex ..... But I've seen the shrinkage comments before, as well as the manufacturers saying the newest foam sheets have been reformulated to reduce the problem. I'm just not sure how many years it may take to confirm the aging issue. That's very interesting, Jack. The oldest EPS foam I've worked with will be three years old next month. I'll have to check into this, when I get a chance, and get back to the forum about it. If it turns out to be true, it will be pretty depressing because the product is fairly easy to work with and I know -- from personal experience -- that it does everything they say it does.
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Post by toomanytoys on Nov 3, 2015 0:46:41 GMT -5
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Post by jimbouk on Nov 3, 2015 0:55:45 GMT -5
Pretty sure I have seen celotex and the like here that have been pretty old and certainly have shrunk a fair amount. However that's when they have been left exposed to the elements for sustained periods ie left in a builders yard for years!
I'm not sure but don't think it passes our regs here to use it as a barrier. As wright said have to use tyvek or similar.
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Post by wrightwoodwork on Nov 3, 2015 1:45:08 GMT -5
Jim on the last job of doing dreaded wimpey homes on the areas that had comb ceilings it was being used as vapour barrier and taped that was the 25mm bridging layer. The layer that goes in between we have to leave an air gap of 25-50mm then over time it starts to curl with the heat. So to stop it 25-50mm battens are meant to be used which prevent it curling up.
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Post by Red on Nov 4, 2015 3:27:08 GMT -5
As I mentioned in my last post, we've worked with both EPS and XPS quite a bit this year. Here's a photo -- taken a bit earlier this year -- of a wall constructed of EPS molded over an internal steel framework. As you can probably tell, the "blocks" are in varying states of condition because they sat on an open trailer for well over two years before the foundation was ready for them. At this point, their third birthday will be next month and they seem to be holding up relatively well. In fact, I measured quite a few of the waste cut-offs this afternoon and their dimensions seem to be nominal. Do you think that the shrinking phenomenon applies only to XPS, Jack?
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