TF shrinking and joining to existing brickwork

[Ben100]

Hi All,

 

I'm bumping this question up from another post I made.

 

I'm looking at building a TF extension to an existing brick house, which will have a roof linking the brick and timber. When the timber shrinks I'll have a lopsided roof...

 

Has anyone dealt with this before or have any ideas?

 

Thanks,

Ben

[Declan52]

How much the timber will shrink all depend on how wet the timber gets during construction.  It will expand during the build and then over 18 months when it is covered over will gradually shrink.  

Who you get to design the frame will take into account these aspects and allow for it.  Your not going to have a roof shrink by  a massive amount to cause it to be lop  sided unless something had went majorly wrong. 

Even if you build all brick and block you will still get settlement and shrinkage cracks. 

[Jeremy Harris]

FWIW, our timber frame has barely moved in the five years it's been up.  Any movement should be visible around the top of the two storey high gable window, which is resting on the slab and has an aluminium outer frame.  When I was up a ladder inside cleaning the windows a few weeks ago I could see a hairline crack around the frame and the plastered walls internally (which are screwed directly to the frame).  If I had to guess, I'd say the movement was at most around 1mm over a height of over 5m.  The sealant around the windows can easily cope with movement that's a fair bit greater than this, I think.

[Ben100]

Ok, cheers guys. Sounds like this isn't as much of an issue as I thought. One of my other posts in the Brick & Block forum raised this as an issue.