Garage opening detail

[flanagaj]

Can someone cast there eye over the image below and tell me whether this is the correct way for building the garage reveal.  I want the garage door to sit behind the opening, but unsure how the internal block leaf will tie into the returning brick course and whether the cold bridging will be problematic.  My plan was to then use a granite setts between the two reveals and up to the garage slab / DPM upstand.

[Mr Blobby]

Assuming the black line is the garage door inside the reveal (as sectional doors are typically installed) then the inner leaf adjacent to the door should be thermally broken with a strip of PIR.

This is because the reveal is on the cold side.

[flanagaj]

26 minutes ago, Mr Blobby said:

Assuming the black line is the garage door inside the reveal (as sectional doors are typically installed) then the inner leaf adjacent to the door should be thermally broken with a strip of PIR.

This is because the reveal is on the cold side.

But how do you thermally break with PIR.  Do you have a drawing or an image that shows this?

[Nickfromwales]

Is this attached or detached? Fire regs may need that closed and FR.

 

Closing as per the pic is normal, and garages are classed as cold ventilated spaces so why would you care about a small cold bridge when the whole garage is 'cold'?

[flanagaj]

6 minutes ago, Nickfromwales said:

Is this attached or detached? Fire regs may need that closed and FR.

 

Closing as per the pic is normal, and garages are classed as cold ventilated spaces so why would you care about a small cold bridge when the whole garage is 'cold'?

Garage is attached.  You are most likely correct that the cold bridging will be negligible and I can close off as per the diagram.

[Nickfromwales]

3 minutes ago, flanagaj said:

Garage is attached.  You are most likely correct that the cold bridging will be negligible and I can close off as per the diagram.

Indeed! Just be sure to properly close any cavities, above the garage door / pedestrian doors & windows to make this properly FR. BCO's sometimes forget this, and one previous instance saw a head of doorway almost closed with only a 5mm strip of uPVC across the cavity; I chirped up and he quickly "added that to his list"...............as that needed to be closed with mechanically fixed FR PB, with all joints sealed with intumescent caulk.

[flanagaj]

27 minutes ago, Nickfromwales said:

Indeed! Just be sure to properly close any cavities, above the garage door / pedestrian doors & windows to make this properly FR. BCO's sometimes forget this, and one previous instance saw a head of doorway almost closed with only a 5mm strip of uPVC across the cavity; I chirped up and he quickly "added that to his list"...............as that needed to be closed with mechanically fixed FR PB, with all joints sealed with intumescent caulk.

One other question.  Do I finish the slab at the back of the inner leaf blockwork or should the slab come through the opening and finish level with the exterior leaf.  If I do the later, do the bricks that close the cavity just sit on top of the lean cavity fill (left image) or should they sit on the concrete slab (right image)  

Eg, if you were looking at eye level from the front would it be the left or the right image below

Edited 20 hours ago by flanagaj
Added image

[Mr Blobby]

2 hours ago, flanagaj said:

But how do you thermally break with PIR.  Do you have a drawing or an image that shows this?

 

Like this...

 

 

This is how ours is built.  The bricklayers put a strip of PIR about 40mm wide into the blockwork.  If I get down the site later I'll get a photo.

 

Edited 19 hours ago by Mr Blobby

[Nickfromwales]

5 hours ago, flanagaj said:

One other question.  Do I finish the slab at the back of the inner leaf blockwork or should the slab come through the opening and finish level with the exterior leaf.  If I do the later, do the bricks that close the cavity just sit on top of the lean cavity fill (left image) or should they sit on the concrete slab (right image)  

Eg, if you were looking at eye level from the front would it be the left or the right image below

Wouldn't the bricks start at slab / TOC  (top of concrete) with the DPC? Looks too emphasised there (imo). 

[saveasteading]

I like to stop a slab short of the inner leaf, then the ramp down is from there and the door bottom seal sits on a slope and water doesn't get through.

This is because bottom seals dont really seal, but water gives up climbing the slope after about 50mm.

 

To form this edge the shutter is simply placed against the inner leaf with any extra packing needed. This assume you now where the bottom of the door will be.