Installation layer or not?

[Fredrik K80]

I have an isolated exterior wall with old plastic. I will replace it with proper age-resistant construction foil. Then plywood will be screwed on.

Should I screw the plywood directly onto the frame studs (which will then perforate the construction foil) or should I build an installation wall with horizontal 45/45 studs and screw the plywood onto these studs?

 

[tergo]

it's fine to screw directly onto the reglarna

 

[Fredrik K80]

it works well to screw directly onto the studs

No problem with the vapor barrier being perforated then? Partly by the screws for the plywood (maybe that's unavoidable) but especially by everything that will be screwed onto the plywood

 

[tergo]

No problem if the Ångspärr becomes perforated then

No, if a screw goes through the plastic, the plastic seals tightly around the screw.

 

[Fredrik K80]

No, when a screw goes through the plastic, the plastic seals tightly around the screw

Vertical or horizontal plywood?

 

[BirgitS]

Why plywood instead of OSB?

 

[Fredrik K80]

Why plywood instead of OSB?

After asking around with both carpenters and generally handy people, the answer has been the same - plywood is much more robust and has a higher quality. OSB is described as if they gathered all leftover wood scraps and then glued them together. This simply becomes an inferior board.

 

[BirgitS]

OSB is enough to hang all common things. Plywood is used in bathrooms, but it should support the weight of a fully loaded vanity that someone sits on half a meter out from the wall. OSB is probably the most common behind drywall in regular walls.
A single wood screw in drywall+OSB can handle 266 kg in vertical load and 169 kg load straight out from the wall, and plywood 4 resp. 22 kg more, see here: https://www.byggahus.se/forum/threads/infastning-osb.345815/post-3324469

But it's your money, so of course, you do as you wish.

 

[Fredrik K80]

OSB is sufficient for hanging all regular items. Plywood is used in bathrooms, but then it has to withstand the weight of a fully loaded vanity with someone sitting on it half a meter out from the wall. OSB is probably the most common behind drywall in regular walls.
A single wood screw in drywall+OSB can handle 266 kg in vertical load and 169 kg load straight out from the wall, and plywood 4 and 22 kg more respectively, see here: [link]

But it's your money, so of course you do as you wish.

It's only 10 m2 that will get panels, so it will only be a few hundred SEK more expensive.