underlay? solid t&g

[deanmacken]

Hello again. just about to lay (finally) Solid 20mm T&G oak on top of existing pine t&g floor. have been advised to use sisalkraft 420 building paper between the layers. just wanted to ask too is there any merit in using the 3mm foam stuff too? sub floor is even, i'm only thinking of it for sound deadening and insulation.

one more thing, i have seen a lot of advice to overboard with ply when laying in the same direction as existing floor. is this just because of uneveness? would like to avoid because of thickness.

TIA

Dean

 

[WoodYouLike]

Yeap, you need to overboard the existing boards when you install the new boards in the same direction: cupping, unevenness etc of the existing boards, and also to prevent the joint of the new boards playing directly over a joint of the old boards (draft)

 

[deanmacken]

Forget to say, i'm secret nailing...

Thanks for the reply woodyoulike. - is it because of cupping in the old boards or to prevent it in the new?

Any thoughts on using spongy underlay with secret nailing?

BTW, do you sell osmo products?

 

[WoodYouLike]

Underlayment has no use if you're secretly nailing, the foam will be compressed at the places where you nail and could create 'springy' areas.
(It's a case of either or: either use underlayment and install the floor floating OR scret nail the new boards to the ply or existing boards, not a combination of two methods)

Yes, we sell many brands.

 

[deanmacken]

Thanks