New French Doors - Outer cavity height question

[Cabbyfan]

Hi everyone,

I am about to have French doors fitted to replace a (narrower) window. The wall is a cavity, block loadbearing internal and standard brick outer non loadbearing. I have already removed the inner leaf fitted a new steel beam to support the wall plate (its a bungalow if that matters).

My question is how to deal with the outer leaf brick work ready for the cill. The law of Sod means the current inner floor level is halfway up the brick. The doors are being fitted by a window firm but I am preparing the opening and making good on the inner after.

Cavity closers will go in before the doors are fitted.

So questions:-

1. Should the outer level of brick be level with the inner flooring and if so is there a good way to do this ? (the outside is brick to floor level; then dashed).
2. There is a DPC a course down on the inner and outer leafs, do I need anything direct under the cill ?
3. Should I fill the cavity under the cill with insulation ?

Thanks chaps.

 

[Gazman16]

1. For sizes you need to have a word with the fitters. It will depend on what size they have made the door, What cill and threshold they have gone with and weather the door opens in or out.
Assuming noone is available to pop around and go over those things with you before hand just take it down to that brick course and when they arrive ask the lads. You can then either take out the full course or run a disc cutter across while the boys drink the tea and eat the bacon buttys that you have prepared for them

2. PVC is water proof so acts as a DPC itself but a bit of DPC is good practice and helps to prevent a bit of cold bridging.
3. As you are making it wider with structural alterations I assume building control is involved? If so have a word with the inspector to see what he will want (they all like different things) Personally I would take out another course or 2 of bricks on the inner layer and extend the timber floor across with DPC (and maybe insulation) where possible.

 

[Cabbyfan]

Thanks for the reply Gazman16.

Doors open out and they ideally want the outer brick course level with the inner floor. I have a saw in the garage so cutting out isn't a problem its just how to best level the brickwork withoyt having a huge hole in the back of my house for 5 days lol.

BC are quite happy with works so far, they will inspect once the opening is done and the cavity closers are fitted. They have already been onsite looking at other things so all good. It was them who insisted a steel go in to support the wall plate replacing what was a wooden lintel.

 

[Gazman16]

As the doors open out you could possibly bury the 30mm PVC cill below internal finished floor height so you have a nice low threshold height preventing a trip hazard. This may mean they would have to put an addon on top of the door though depending on what size the have made it.