Timber Ceiling Joists

conbue

Hi All,

We have gone for timber ceiling joists instead of Ducon slabs for our story and a half. Should i treat the joist ends where the will sit on inner leaf of block. Also what's best option for sheeting out the joists, will OSB get destroyed when exposed to weather for upto 2 months?

BryanF

put the Joists on hangers. And figure out your air-tightness layer/strategy before doing anything.

C. Eastwood

https://www.boards.ie/discussion/2058278772/timber-ceiling-joists

There is absolutely no need to treat the ends of the timber above DPC with preservatives.

However, after a short period of time the joists will dry out to a lower moisture content, which will result in shrinkage and cause a gap of approximately 1 mm at the sides and top of each joist- which will allow draughts and result in heat loss by Convection.

I agree with the recommendation above - fit metal joist hangers.

grimeire

Timber is always supposed to be threated or wrapped in dpc when in contact with concrete.

Hangers is what you are supposed to use for air tightness but they are expensive. They are also slower to fit.