advice on garden room

[Hardcore]

Hi - I'm busy building a garden room and the roof will all lean one way at 7.5 degrees and be fitted with 3 velux windows (flat roof models). Roof beams are 200x50x5400 and some need to be doubled up around velux windows and one is 3 bolted together due to roof design.

The same size beams will be bolted to the house wall to form the wallplate.

I have a few questons.

As I will be using metal wall hangers fixed to wallplate how should I cater for the doubling up or the 3 bolted together as I cannot see a way to use 2 or 3 wall hangers together as the beams are bolted together?

The other question is in regard to vapour barrier. This will be a cold roof with the insulation under the roof and between the beams. Celotex XR4000 @ 150mm thickness fitted between beams and celotex TB4020 below that covering the whole of the celing underside. Using special tape for the joints TB4020 will provide the vapour barrier...but I intend to fit spotlights so this will make holes in the TB4020. So do I need to fit and extra vapour barrier above the XR4000?

The roof soffet end will of course have vents but do I need to put vents in the roof at the peak next to the house wall?

Finally roof will be 18mm osb and sealed with Classicbond 1.5mm EPDM.

Thanks for any advice.

 

[motorbiking]

Since it’s attached to your house it’s going to be subject to building control. What about bolting a wall plate beam to the existing wall to support the roof bearers? Alternatively search for wall hangers that are wide enough. You can get hangers 150mm+. For the down lighters are these low heat LEDs? Holes under 150mm are allowed.

 

[Hardcore]

Hi..thanks. It is being inspected by BC and maybe I did not explain correctly but I am rawl bolting a wall plate beam to hang off roof bearers using timber to timber joist hangers. The question is I cannot see a way to fit two or three of these hangers next to each other to carry 2 or 3 roof beams that are bolted together.
Where 3 are bolted together I can fit one to each outer beam but not the central beam. As for 2 beams bolted together I can only fit one joist hanger. The unsuported beams can of course be glued and nailed to the wall plate if that is the only solution.

Thanks for the advice on the down lights but this still breaks the vapour barrier.....I read this must be maintained behind the lights or the other option is to install a lower celing below the vapour barrier and use low profile LED lights.

Kind Regards

 

[motorbiking]

I don’t think you’ll have a problem with the lights as long as you accurately cut the holes. For the wall plate is there any way you can attach the triples before the plate goes on? Then you can screw from behind.

alternatively sistering them (bolt through) should be ok as long as the hangers can take the load.

 

[domdee]

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