How do I finish the cavities left behind by an inept door installer?

[Gazza1980]

Hi, does anyone have any tips on how to finish the cavities left behind by an inept door installer? As you can see, the doors have been mounted on the outer leaf of the external walls. They mounted the doors splints of wood, and squirted expanding foamed in the gaps.

 

What they didn’t do is to install a cavity closer before installing the doors. So, I’m now left in a quandary as to what to do. Some builders have suggested filling the cavity with concrete. But, this would cause cold spots, cold bridges and also lead to damp issues.

 

Other builders have suggested removing the top row of bricks, filling the cavity with fibreglass insulation, and then reinstalling the bricks at a 90-degree angle to create a cantilevered cavity cap.

 

So, what is my best option in this instance? Can you think of alternative solutions?

 

I should mention that the cavities are around 60mm wide and about 600mm deep. They are also a bit of a mess, with wall ties, rubble and such like here and there.

[Mr Punter]

I don't think this is down to the door installer.  Perhaps look at removing the top course of bricks and replacing with high compressive strength EPS.  What is the floor finish?

[crispy_wafer]

 

initial thoughts are - I'd remove the bricks and the pir that's up against the screed, get some xps (marmox/jackoboard) etc cut and bond a couple of layers together so it's like a long plank put that into the cavity, create an upstand against the outer leaf and bond that to the plank you dropped into the cavity then fill with screed.  Alternatively bond more layers of xps up to just under the screed level and pour some self leveller over it.

[Gazza1980]

2 hours ago, Mr Punter said:

I don't think this is down to the door installer.  Perhaps look at removing the top course of bricks and replacing with high compressive strength EPS.  What is the floor finish?

It's a screeded floor, Mr Punter. It's about 70mm thick, on top of PIR board and DPM.

[Gazza1980]

1 hour ago, crispy_wafer said:

 

initial thoughts are - I'd remove the bricks and the pir that's up against the screed, get some xps (marmox/jackoboard) etc cut and bond a couple of layers together so it's like a long plank put that into the cavity, create an upstand against the outer leaf and bond that to the plank you dropped into the cavity then fill with screed.  Alternatively bond more layers of xps up to just under the screed level and pour some self leveller over it.

I like this idea. Thank you. Would you PIR to the bottom of the cavity?

[Big Jimbo]

Does the door frame lap into the insulated cavity by a minimum of 30mm ?

If not, and it don't. then welcome to a nice thermal bridge, and a fail of building regulations.

[MortarThePoint]

I can't see, but is the door frame on top of a timber cill?

 

 

4 hours ago, Mr Punter said:

What is the floor finish?

 

I think @Mr Punter is asking what your final floor finish will be. Tile, Timber, Carpet,...

 

Edited 18 hours ago by MortarThePoint

[Gazza1980]

2 hours ago, MortarThePoint said:

I can't see, but is the door frame on top of a timber cill?

 

 

 

I think @Mr Punter is asking what your final floor finish will be. Tile, Timber, Carpet,...

 

Hi, the door was installed on top of several wooden lengths, laid perpendicular to the brickwork, and then filled with expanding foam.

 

Ah, yes, my mistake! I'm laying Woodpecker laminate flooring directly on top of the screed. But, the flooring is lower than the lowest edge of the door frame. So, I'm planning to install an small oak step at the bottom of the door opening - so, directly over the top of whatever I use to close the cavity. Otherwise, the Woodpecker would run up to the wood and foam beneath the door frame, and this would be visible.

[Gazza1980]

6 hours ago, Mr Punter said:

I don't think this is down to the door installer.  Perhaps look at removing the top course of bricks and replacing with high compressive strength EPS.  What is the floor finish?

Apologies, I misunderstood your question. Here's my revised response!

 

Ah, yes, my mistake! I'm laying Woodpecker laminate flooring directly on top of the screed. But, the flooring is lower than the lowest edge of the door frame. So, I'm planning to install an small oak step at the bottom of the door opening - so, directly over the top of whatever I use to close the cavity. Otherwise, the Woodpecker would run up to the wood and foam beneath the door frame, and this would be visible.

[MortarThePoint]

How much higher do you think the oak step will be than the top of the woodpecker flooring? Planked flooring normally has it's long axis perpendicular to a door like this so has some strength to cantilever over a 60mm wide gap particularly with a timber over the top. If the woodpecker flooring is thick enough to be used over joists without a sub floor then it's should be fine, you just have to make sure any planks don't flip up if trodden on, but unlikely anyone would tread that close to the door.

 

That would remove any structural requirements from what you put in the cavity 

[JohnMo]

I'm a bit confused. Is this a new build a renovation or something else? A drawing would help showing what was planned and what you got.

 

What is the wall construction? 

 

The doors and windows have to straddle wall insulation, if it's doing that, the detailing on the floor is rubbish. If windows and door are not a straddling the wall insulation, get the installer back to fit them correctly.

 

Does you floor match what the walls are doing with respect the cavity?, if so the door looks from the photo to straddle the cavity. 

18 hours ago, Gazza1980 said:

What they didn’t do is to install a cavity closer before installing the doors.

Was that work agreed to was that shown on a drawing they worked to etc - if shown on drawings and they agreed it was in there scope, get them back to do the job correctly.