Advice needed on cavity below french door and inside floor.

[johntool]

Hello there. I'm cutting a hole for a french door to be installed and need advice on the floor preparation. As the bricks at floor level are just above the level of the inside floor I'm going to have to take out that level of bricks and replace them with something lower as not to exceed the height of the inside floor. Thinking about it, as I've got the stone cutter, would shaving that layer of bricks in half be a better idea? But how do I fill the gap between the 2 courses of bricks and keep a watertight seal. Do I just fill with concrete upto the height of the damp proof course, put a damp proof membrane on top of that and then level it all off with another layer of concrete. I've attached a few photos and any advice would be very helpfull.

PICS:
http://i176.photobucket.com/albums/w182/johnsmoker/4.jpg
http://i176.photobucket.com/albums/w182/johnsmoker/2.jpg
http://i176.photobucket.com/albums/w182/johnsmoker/3.jpg

 

[willroy]

Hi just done something similar but on a new build.The french doors if fitted to the level of the damp coarse would have been a brick high above floor level.I wanted the door opening at floor level so removed the outer wall of one brick high to fit the french door leaving the inner wall as is.The door was then fitted so just above floor level.Damp coarse was replaced .When croncreting visquine should be placed underneath to prevent damp rising.

 

[johntool]

Does the visquine bridge the gap between the outside bricks and inner floor. i.e you extend the dampproof membrane across the cavity gap with the visquine and have a cavity under that or do you put the visquine at the bottom of the cavity at ground level and then fill with concrete up to the floor level?

 

[willroy]

Put the damp coarse across the cavity may be tricky if you have different heights ,then with overlap tape to membrane on existing floor if there is one.

 

[chessspy]

Hi, johntool,
If I may politely crit your piccys, they are not very informative.
If you switch from
photobucket to picasa, you will find you can take as many pics as you like, upload them in seconds, and fill an album with as many views as you like , and the people who want to look, can acess them also very quickly.
you should arrange it so that the bottom of the cill of your french doors is installed below the level of the internal floor finish.
Then the 'step over' will be minimal, (no trip hazard)
If you uncover a cavity space when you cut out, as you have/will, between the outer and inner brick skins, then clean out any bubble at floor level, fit the doors to the inside of the outer skin of brickwork.
And bridge the gap with whatever finish floor you wish.
the necessary dampproofing steps you need to take should be fairly obvious