Closing cavity on a garage?

[iDIY]

Hi Guys,

I am building a detached double garage with proper foundations, a concrete floor and cavity walls with insulation in the cavity to make it warmer when tinkering inside.

I read elsewhere that it's normal to close the cavity at the door opening with brick/block as opposed to leaving it open and fitting cavity closures due to the weight of the door.

Firstly, is that correct and if so, should there be DPC running vertically up and across the door aperture as it effectively bridges the cavity?

 

[noseall]

Yes, exposed blockwork in areas such as a garage would mean that you close off the reveal jambs with masonry and vertical DPC.

and across the door aperture

There will be a cavity lintel across the door, surely?

 

[iDIY]

There will be a cavity lintel across the door, surely?

Yes, sorry I didn’t mean across the top, I meant across the vertical cavity between the door frame and the brickwork. I’m thinking even with a vertical DPC the doorframe is breaching the vertical DPC ?

 

[noseall]

I’m thinking even with a vertical DPC the doorframe is breaching the vertical DPC ?

Yes, the frame can straddle the DPC. This method is preferred. It means at no time is any of the external masonry visible internally - thus no cold bridge. The closer to the centre of the frame the better. Bugger to fix though.