Pouring a concrete garage floor..

Hi,
I'm in the process of extending my existing single garage tuning it into a double. I've just pored the foundations and about to set out on the brickwork up to the DPC.
The double garage won't have an internal wall, so the current wall will come down at some stage - the question is when.
It would be really convenient for me if I could build the whole of the new external wall, then knock down the internal wall and lay the new floor. Alternatively, I knock down the wall, lay the new floor, carry on building the new external wall.
It would certainly be more convenient for me to knock down the internal wall later rather than sooner, simply because I have stuff stored in the garage. By knocking it down last I can put the roof beams in place on the new garage and have a tarpauline over.
The architect drawings shows the concrete base laid over sand/hardcore, then on top of that is the waterproof membrane and screed layer.
Two things that concern me.
Leveling the floor when you can't get at it from both sides without walking through the concrete, and I'm not sure if the damp-proof membrane that runs under the screed needs to run through into the brick DPC or not.
Any specific pointers around on web sites about laying concrete floors like this?
Thanks,
Paul
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Paul Andrews wrote:

Oh., No brainer. Leave the orignal wall till all the structure is up, knock it down to the old damp course, lay yer new membrane over that (and over a load of hard core etc with sand/cement to smooth it) and screed or concrete the new floor up to old level..
Laying the final floors was about the last thing that happened in my house.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

a
snip
like
house.
The existing DPC is higher than the garage floor level, so it woun't be possible to do that. I plan to take the wall down well below the existing slab level. The construction details show the initial pour will be over hardcore and the screeding will be above that resting on a membrane above the lower slab. I have to tie together the new and old slabs using steel dowels. I'm not entirely sure how that's going to work in terms of the new membrane, since I suspect that the existing floor might not have a membrane and to tie the existing floor to the new I don't want to have the new membrane sticking through the join!
Anyway, I'll take your lead and build the outside walls first before removing the existing side. I'll probably remove a few bricks to see what's happening with the existing slab.
Thanks for the feedback,
Paul
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 27 Jul 2005 13:40:09 GMT, "Paul Andrews"

What I am doing is this :-
I put 300mm wide DPC into the wall, so it hangs out a good bit. then build the wall upto the roof, with just the dirt on the floor. I will then level the dirt, and join the underfloor DPM into the wall DPC, you can get some special supper sticky souble dided tape for this. My architect tells me, that the DPM you put under the floor is not suitable to use as a DPC in the wall.
Rick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.