Summerhouse Roof Help

[Candyman21]

Good Evening All,

The brick work is half way up on my summerhouse house now and the roof is really causing me some stress! Its 4m wide and 3m deep, with a 50mm cavity, brick external leaf and thermalite inner leaf. Its withing 2m of a boundary so i can only go to a maximum of 2.5m in total height. Its on a slope so i am taking the 2.5m from the natural ground height at the highest side.

The slab is 3 courses high of 65mm engineering brick, so this is about 225mm in total. This gives me around 2275mm to play with to get to the finished height. On the front it has an opening for a door 1100 wide, then 400mm of brick work, then 2 600mm windows. I am going to finish the top of the windows and doors at 1900mm, not very high i know butt i am under 6 foot

So this leaves me with 375mm to play with, i just cannot get my head around around how to do the roof. I am going to be using an epdm roof.

Do i add some form of lintel and brick up another 3 course so around 250mm (facing bricks are 73mm) and add the beams to the internal blockwork,if so how would i secure them to the inner leaf? This would then leave me with around 125mm for firrings, ply and rubber membrane.

Or do i add a wall plate front and back and put the beams on top of this? i take it i would still need a lintel to support the wall plate over the windows and doors, i cant really work this out as i have no idea how tall the lintel is?

I am really sorry that you have had to read all the ****e above but i would really appreciate some advice as i have no idea what to do for the best, as you can tell!

Thanks

John

 

[Notch7]

Id be tempted to do a wall plate on inner skin say 2no 4 x 2. You can sit the wall plate into an angle steel to act as the lintel.

You joists would be say 7 x 2 over a 3 metre span. However if you want a 100mm insulstion over, thats going to be a 300mm thick roof.

Alterantively you could fit 2no 5 x 3 universal beams which could sit in line with the 400mm brickwork. That would allow you to use 4 x 2 joists.

I would make doors and windows finish at higher level -make head of these frames part of roof fascia.


Note: thoughts only, actual sections sizes to suit loadings.

 

[Candyman21]

Thanks Notch7 for the reply,

So something like this?

https://www.less2build.com/lintels/...le-Leaf-Lintels/STRESSLINE-SINGLE-LEAF-1500MM

Would this just be bedded onto the inner course or would it be fixed somehow? Would you then just use straps to hold the wall plate in place around the inner course, would you secure it when it lies over the lintel?

I quite like this idea, so may go for this one as it seems the easiest to achieve.

Thanks Again

John