Wall plasterboard, EI30, seal gap to ceiling plasterboard?

[Johan H]

Double gypsum board is installed in the ceiling, mounted first. Then OSB + single gypsum on the walls.

Neither the OSB nor the gypsum on the walls are flush against the ceiling gypsum (difficult to achieve that).

How do you "seal" this gap, which is 5-10 mm? I assume regular caulk isn't ideal, fire-wise.

I saw that there is gypsum compound at Gyproc (G66), but it "doesn't adhere to wood". That's a bit difficult, since it's OSB there...

Tips?

 

[HandySmurf]

There is sealant that is fire-rated. It's likely available at your nearest hardware store. If the gap is large, there are also fire-rated packing materials. I have used sealant myself when building walls with EI60. Where I had large gaps, I first inserted such "tube" in foam plastic and then applied the sealant on top to make it tight.

You can use, for example, this one: http://katalog.essve.se/#/?article=V70-wc62863-
(go to FireSeal fireproofing and then there's a product called FireStop 1000)

 

[Johan H]

Great. But I think I should use Fireseal FireStop 100, which is acrylic-based (if it should be possible to paint on it)? FireStop 1000 seems to be silicone-based

 

[HandySmurf]

Just checked what the one I used was called and it was FS 701. It is acrylic-based. Tremco is the manufacturer.
http://www.tremco-illbruck.se/produkt/01182_index.html
Use bottningslist if you have a large gap.

 

[Matti_75]

Checked now what the one I used was called and it was FS 701. It is acrylic based. It's Tremco that manufactures it.
[link]
Use backer rod if you have a large gap.

Stop now!! Absolutely no backer rod. You must fill the entire joint with the sealant otherwise it serves no function. It is very important to read up before you start fire sealing.

 

[HandySmurf]

Stop now!! Absolutely no backer rod. You must fill the entire joint with sealant otherwise it serves no purpose. It's very important to read up before starting to fire seal.

Yes, it is important to read first and apparently you haven't done that. It is clearly stated in the data sheet for FS 701 that backer rod should be used to get the correct joint depth.

I myself had triple plasterboard, resulting in a 13x3= 39mm deep joint.

 

[Matti_75]

Now it was Fireseal that TS was talking about.