Pitched Tiled roof support

[cpbobo]

Hi, We have a single story rear kitchen extension. It was a self build built approx 20 years ago by previous owners. It was not the best build and had a flat roof with tar and felt (Typical of that time). 2 years ago we put on a pitched tiled roof over the flat roof. My question is could there be an issue with the extra weight from the tiled roof on the kitchen walls. I am not sure what the original foundation was like on this extension? Also I am seeing a lot of the plasterboard joints from the kitchen ceiling crack but I believe this to be from the joints themselves. Any words of wisdom appreciated..

 

[Ron]

cpbobo...this is not a DIY site, but considering your question, you should have gotten a structural engineer involved with this at the beginning. Yes...a tile roof imparts significantly more load to the supporting structure than shingles or unsurfaced built-up roofs.

 

[msquared48]

I have to agree with Ron here...

Don't know where you are, but depending on the kind of tile, it can at least double the dead load. Won't affect the snow load though.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[cpbobo]

Hi, It is a single story 9 inch cavity block extension. What typically load would a single story 9 inch cavity block wall take? What signs of structural druess shoudl I look out for? Roor was built with 45 deg ridge with hip boards and wall plate. Thanks for the replies..

 

[woodman88]

Was the original structure a single story with a tile roof?
With block walls I would be concern with them being self built or even sub out to a handyman to be built. If the pitch roof was not design to clear span over the addition but supported on the flat roof, then the flat roof framing may not be meeting the code requirements for deflection and/or strength.
As Ron stated, you should have had a local engineer to look at your situation before adding the new roof. Especially with a self built addition.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[BAretired]

The good new is that it's not too late. Get a structural engineer to look at it now.

BA