Insulation choices
Hello, thanks prematurely.
I am renovating a wall in my lounge. It looks like there wasn’t any insulation beforehand.. I’ve a sense there’s no or little or no insulation all through my condominium. It is Amsterdam and previous.
There are to be two layers of drywall.. although perhaps the interior layer is a kind of insulation?? Within the first pic you may see the darkish brown wooden which is the roof on an angle… The second pic reveals a shot of the two layers of drywall
Is that interior layer of drywall truly a kind of insulation? what are my insulation choices? does it make sense so as to add insulation if the remainder of the room would not have any? or ought to I wait and get the condominium correctly insulated by some firm?
thanks
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[roof on an angle](https://preview.redd.it/ogbwbrozz6za1.jpg?width=4032&format=pjpg&auto=webp&v=enabled&s=8436b2c39683cb7f138c2dd90d727125cf234a84)
[2 layers of drywall](https://preview.redd.it/qnv2ily007za1.jpg?width=4032&format=pjpg&auto=webp&v=enabled&s=7c9eee0ae2a34eb9c7e729d5fcb8d666d675e3f8)
Comments ( 28 )
Is this an interior wall? You won’t find insulation in those.
You have two layers of drywall. Normally in NL the non-inside room layer (according to current practice) would be OSB (oriented strand board) with drywall on top, but you have 2 layers of drywall instead.
No point insulating a small part, unless you do it all.
That is old and very likely to have asbestos in the mud. Have you had the mud tested?
Even if the rest of the room has no insulation, adding some here while you have the wall open is a good idea. Even if you don’t have the entire wall open, punching some holes in the upper parts of all the stud bays and blowing in insulation would be a good idea, since you’re already committed to significant wall repairs. Adding a bit more to close the blowholes won’t expand the project much, and you’ll enjoy a much warmer, quieter room afterward.
The second layer of drywall is a thin (probably 6mm) “renovation” drywall, used as a quick way to get smooth even walls when redoing a room.
Perhaps look into a spray foam layer, then add fiberglass batting or blow in insulation.
Doing a small amount of insulating won’t make much difference until you’ve done at least 75% of a space.
Between the outer wood cladding, two layers of drywall, and the air gap in the wall cavity.. I would spitball that the wall has around R2 worth of insulation as it currently is.
Not a lot, but it’s something.
edit: why the downvotes? do the math yourself if you think my numbers are off – https://www.ahfc.us/iceimages/manuals/building_manual_ap_1.pdf
I’m going to bet you could just stuff this full of fiberglass and never think about it again and everything will be perfectly fine. That said, it might be good to get some local advice for this specific roof situation. There are some situations where blocking off a roof area like this could limit ventilation to the attic spaces. Another consideration is moisture barriers, I don’t know if NL uses them or not.
I also need to disagree with the other poster. Insulating this area, even if the rest of the room isn’t insulated, will still help. Every bit helps.
You need to follow the building code for your area on how to insulate the space, vapor barrier as needed, etc… and replace the drywall for fire ratings.
You may want to hire a professional if this is not your area of expertise.
I bought an old house with no insulation. One wall was opened up for a new window and I put in roll insulation. Also have insulation in a new room in the back. There is a huge difference in the temps of the rooms in the winter. I’ve been concerned about mold in the old part where I added some. If I had it to do over I would also put in some tyvac. Roll insulation gives you more warmth.
You should be somewhat mindful about how you insulate, as installing insulation in old buildings can often lead to unanticipated problems, mainly to do with moisture. Some things to consider are whether you should have a vapor barrier based on your local climate, and in your case, if this roof space is, or should be ventilated to stop moisture accumulation. Based on the limited information here, it would be difficult to give informed advice here, but it may be worth discussing with local builders or designers who are familiar with local best practices. You don’t want to end up with a situation where you’re getting moisture accumulation within the wall/roof that will cause deterioration and an unhealthy environment.
You want a ‘spijkerflensdeken’ for the angled roof in a thickness that is slightly less than the depth of beams. Thicker and it can bend the drywall over time.
Because it’s sealed you don’t need to add vapour barriers.
I recommend you ask this in the Dutch sub /r/klussers so you can get advice with knowledge of the local materials and construction methods.
In a roof you want high r-value. Close cell spray foam is the highest r-value so that is what you want. Unless the pictures are optical illusions you don’t have enough space there to get a good r-value even with closed cell foam, so everything else should be out. Typically the cost of hiring a pro is the same as doing it yourself, and they have equipment and experience to do it faster than you.
Beware of vapor barrier problems that others have mentioned though.
That second layer of drywall is likely just due to laziness (though I’m not sure if this is done in Amsterdam or other places for reasons I’m unfamiliar with, I’m in the US, so my info is US-centric). It wouldn’t really provide much insulation above the air it displaced.
I would add insulation if I was already working in the walls; though if it’s an interior-only wall I might not (unless I wanted sound damping). Roof insulation requires some consideration though (likely specific to your area), roofs often need airflow for various reasons; again US-centric info, but my house the roof is completely uninsulated, but the floor of the attic under the roof is insulated.
I would take a look through your local building codes. A lot of this type of advice has to be specific to the region, and a lot of the comments on this thread are giving advice about their own regions without any recognition that wall assemblies are not equally performant across all climates. Coming from a climate very similar to Amsterdam (what a beautiful city yours is!), our local codes require ventilation along the underside of the roof sheathing, so that any dampness in it can be dried out as air passes over it. In my region, there are these thin styrofoam baffles you can staple on to the roof between the rafters which basically prevent the insulation from sitting directly against the sheathing, and allow continuous venting from bottom to top. After insulation, I would install a vapour barrier and then new drywall against that, but that configuration is due to being in a cool marine humid climate, where you want vapour barriers on the warm side of the wall assembly; the opposite is true for warm humid climates, where you put the barrier on the exterior side, as houses there tend to have cooler insides than outsides for most of the year.
I would be tempted to insulate this area despite not doing the whole thing; it will make a noticeable difference. However, if I were you I would throw out all the advice I got on this thread as much of it is inapplicable to your climate and it will be very hard to sort through what is correct. Looking for localized resources and building codes will be the best route to finding out what is appropriate for your building to ensure you don’t accidentally create a vat of mold behind your brand new wall.
Please be careful with advice you get on here. Most are Americans who have people older than most of their houses
Depending on how old your house is, it might have been made to breathe, not be damp proof like a modern house. If the house is not treated in the right way (lime plaster, breathable paints) you could easily end up trapping moisture in the walls and causing damp/rot very quickly.
This is the UK but might be similar.
https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html
Perhaps this is not a problem for you and it’s modern construction but then I would have expected insulation. Just keep that website in mind before you go blowing around non breathable materials. Modern insulatoring companies won’t have a clue by the way.
If spray foam is an option for you that is probably best, especial on an attic wall/ceiling with thin framing members. Nothing else gives you the same r value plus the built in air and vapour barrier.
Maybe also try r/klussers
goddamn Amsterdam roofs. Spend a few winters on the top floor of a gaff on one of the canals with no insulation.
get an extra inch in your rooms by using this one weird old trick
I would highly suggest getting some input from someone closer to you. Reddit is skewed heavily towards the US and our construction methods, practices, and regulations differ from yours. If you mess this up you could cause serious damage to the roof.
To my knowledge Amsterdam (like most of northern Europe) used loadbearing wood structures, a lot in cities back in the day. These needs to be well ventilated, hence no insulation. I can’t tell from the pictures, but my guess it what you have here.
These can stile be insulated somewhat, but when you add insulation you need to make sure there is enough airflow round the old wood. So you need to check building codes.
That type of roof is called gabled. We have a gabled house as well, and we have similar insulation problems (101 year old house).
For the inner walls you could add anoter wooden frame inbetween the existing one, however with an slight offset outwards so that you can get an air gap between the wall. This will remove sound transfer from one wall to the other. Insulation can still be added on top of that, drawback is you lose some space.
https://www.jlconline.com/how-to/interiors/practical-sound-control_o
Just in case… Here, in NZ two layers of plasterboard are usually used as per regulation for fire-walls; maybe also check if that’s the case where you are ?
Rock wool
If this was in the UK heres what you’d do…
Add a layer of 100mm thick pitched roof insulation boards tightly packed between those bits of wood leaving a 50mm gap between the roof and the insulation. Which insures that there is airflow behind the insulation.. prevents condensation and rot.
Then drylining board across the face of that and then the drywall boards.