benz
19th Feb 2011, 08:38 PM
Hi all, i'm new here.. have had a bit of a look around but havent seen an existing thread that helps... sorry if there is one and i havent looked far enough through the boards...
I am about to mave an area at the abck of our house - the problem is I have to pave above the DPC out the back.
Some history - the main part of our house is approx 70 years old, the exterier walls are built from stone around 45cm thick, and the internal walls are brick. The original house is all jarrah flooring. I have no idea if any form of DPC was used that long ago. This part of the house has been treated by tech dry ??.. where they drill holes every 100mm or so and inject silicon stuff?... This was done probably 20 years ago.,
Around the same time, not sure if its before or after the silicon treatment though, a new sunroom and laundry was built onto the western end of the house. This has a concrete base with the normal orange plastic sheet under the slab which from what i know is the DPC for this area. The walls in this area are bessa brick, with a mortered outside finish, so no dampcoarse is visible above the slab at all. I have no idea if anything was put in there like happens in modern houses i think.
Now the paved area i wish to do is west of this sunroom. So according to from what i can gather is normal standards I should pave below the plastic sheet under the concrete? If so that would make my paving 200mm plus below florr level.
But the problem is, I live in a fairly flat area and if i was to pave at this height, the paving would be the lowest area for 100m all around, hence it would become a paved pool after every rain event... It is physically not possible to pave this low..
I am looking at paving at a height around 50 to 80mm below the interior floor height, which will be on average 100 mm above where the damp coarse is.
So i am thinking of folding the damp coarse up the side of the concrete to within 5mm of the top of the pavers and then using silicon or liquid nails or something to glue the plastic sheeting to the slab, to prevent moisture getting in. Any thoughts on what might be best?
In my mind, theoretically the only area moisture can readily enter the wall then is the few millimetres where the pavers touch the wall but there is no plastic between them.
I will be building a pergola over the paved area as well, so this wall/paver junction should see very little moisture, and i cant see much moisture capillary actioning its way under 3 metres of pavers, then up into the pavers and then through this few millimetres of interface.
At present where the pavers will go is just dirt... that gets rained upon readily... the curretc dirt level is around the height i want for the pavers and at present the plastic sheet just comes out under the slab and is cut of 10cm past the wall... and its just been covered by dirt... so for the last 20 years the bottom 10cm of my wall has been touching wet dirt with no DPC that i know of above this height. I have some flaking paint etc inside... but not a lot...
Any thoughts, suggestions, comments are greatly appreciated. Sorry this post is such a novel, but i'm trying to give as much info as possible
Cheers
ben
I am about to mave an area at the abck of our house - the problem is I have to pave above the DPC out the back.
Some history - the main part of our house is approx 70 years old, the exterier walls are built from stone around 45cm thick, and the internal walls are brick. The original house is all jarrah flooring. I have no idea if any form of DPC was used that long ago. This part of the house has been treated by tech dry ??.. where they drill holes every 100mm or so and inject silicon stuff?... This was done probably 20 years ago.,
Around the same time, not sure if its before or after the silicon treatment though, a new sunroom and laundry was built onto the western end of the house. This has a concrete base with the normal orange plastic sheet under the slab which from what i know is the DPC for this area. The walls in this area are bessa brick, with a mortered outside finish, so no dampcoarse is visible above the slab at all. I have no idea if anything was put in there like happens in modern houses i think.
Now the paved area i wish to do is west of this sunroom. So according to from what i can gather is normal standards I should pave below the plastic sheet under the concrete? If so that would make my paving 200mm plus below florr level.
But the problem is, I live in a fairly flat area and if i was to pave at this height, the paving would be the lowest area for 100m all around, hence it would become a paved pool after every rain event... It is physically not possible to pave this low..
I am looking at paving at a height around 50 to 80mm below the interior floor height, which will be on average 100 mm above where the damp coarse is.
So i am thinking of folding the damp coarse up the side of the concrete to within 5mm of the top of the pavers and then using silicon or liquid nails or something to glue the plastic sheeting to the slab, to prevent moisture getting in. Any thoughts on what might be best?
In my mind, theoretically the only area moisture can readily enter the wall then is the few millimetres where the pavers touch the wall but there is no plastic between them.
I will be building a pergola over the paved area as well, so this wall/paver junction should see very little moisture, and i cant see much moisture capillary actioning its way under 3 metres of pavers, then up into the pavers and then through this few millimetres of interface.
At present where the pavers will go is just dirt... that gets rained upon readily... the curretc dirt level is around the height i want for the pavers and at present the plastic sheet just comes out under the slab and is cut of 10cm past the wall... and its just been covered by dirt... so for the last 20 years the bottom 10cm of my wall has been touching wet dirt with no DPC that i know of above this height. I have some flaking paint etc inside... but not a lot...
Any thoughts, suggestions, comments are greatly appreciated. Sorry this post is such a novel, but i'm trying to give as much info as possible
Cheers
ben