Brick laying for extension

[NetStorm]

Hello, I am hoping someone can help me with some advice...

I am currently having an extension built on my house. The bricklayers have started with the foundations and have got it up to damp.

They have stopped the cavity where an external door and patio door would be placed, a few people have told me that this is not the correct way of doing this.

Please could you put my mind at rest and tell me if this is correct or not. I have attached some photos.

Regards,

 

[limerockconstruction]

what sort of floor are you having?

 

[NetStorm]

It will be a solid floor, 200mm insulation and 100mm of screed.

 

[limerockconstruction]

Thats a lot of insulation!! Shorts only....

Although i've not done it that way before, as long as the DPM detail is done correctly I see no issue with it. The cavity would need to be filled with lean mix anyway so your floor covering can go on. I see no problems....

 

[NetStorm]

Thanks for the reply, made me feel a lot better about it.

How would you suggest making up the height? without using 200mm of insulation.

The below picture is our current stage, the top of the brick is damp. which is about 300mm above what we are at now.

Regards,

Dan.

 

[limerockconstruction]

DPM detail looks OK from the photo.

200mm seems a lot, even by todays standards, but isn't a problem, its just more expensive. You would usually just chuck in a bit more type 1 to the base or concrete in the slab to increase their relative depths.

It can be done with insulation.

The only thing i'm not 100% sure on is maximum screed depths. We usually do 75mm which would mean 225mm of insulation - getting warmer by the minute!!

 

[freddiemercurystwin]

It really depends on the spec of the insulation, if its 200mm of polystyrene then that’s an economical and practical way of bringing the floor up to match the existing. If its Celotex then I would agree its overkill.

 

[limerockconstruction]

Fair point - haven't really used polystyrene for years now, never enters my thought process.

 

[freddiemercurystwin]

No well it is crap generally but for things like this it can work pretty well.

 

[^woody^]

They have stopped the cavity where an external door and patio door would be placed, a few people have told me that this is not the correct way of doing this.

On the contrary, that would indicate to me that they have thought about the threshold detail and know what they are doing.

Many builders just take the cavity wall across and then have to mess about with the DPM, and threshold