Wall plate or no wall plate?

[smash_it]

Hi All,

I wondered if you guys could shed some light on this one for me. I have a 5x4m garden room made from block with 100mm cavity wall. Nothing too fancy just an extra storage space / sun room in the garden. My question is, can the roof rafters sit on top of the inner block wall using suitable straps hangers etc as opposed to rafters sitting on a wooden wall plate? Just want to ensure I stay within the 2.5m high rule where possible as it will be close with the wall plate too. I am happy to install a wall plate if neccassary but just wondered if essential.

Any advice is much appreciated.

 

[noseall]

Hi All,

I wondered if you guys could shed some light on this one for me. I have a 5x4m garden room made from block with 100mm cavity wall. Nothing too fancy just an extra storage space / sun room in the garden. My question is, can the roof rafters sit on top of the inner block wall using suitable straps hangers etc as opposed to rafters sitting on a wooden wall plate? Just want to ensure I stay within the 2.5m high rule where possible as it will be close with the wall plate too. I am happy to install a wall plate if neccassary but just wondered if essential.

Any advice is much appreciated.

Yes.
Wall plate or not wall plate depends on how you are detailing the eaves. For example, if you wish to build say a parapet, then you would NOT fit a wall plate.
I do like a plate to fix to and strap down. Others prefer joist direct to the masonry with twisted straps.

 

[smash_it]

No parapet, just a basic flat roof. It will have facia board and sofit with a 450mm overhang on the front and a 150mm over hang at the back for ventialtion. I was just not sure if rafters directly on the block was an acceptable practice or not. Makes things a bit easier if it can be done without a wall plate but not end of the world if needed.

 

[^woody^]

There's a difference between "can" and "should".

Yes rafters can sit directly on masonry, but should they? Well, there are issues with loading, rafters pushing out on individual blocks, unevenness in the wall plane or level, cutting the birds mouths, and practicalities of banging the roof frame together and loosening the wall its sitting on.

The plate can be 4x1 if need be. Adjust your top course to allow for a plate, you'll be glad you did.

 

[smash_it]

Sounds like very wise advice to me. Thanks for help guys.

 

[^woody^]

One other tip, strap the plate down before you start forming the roof