looney
4th June 2006, 01:07 PM
I am putting in a ag drain under my town house (.5 to 1.5 m clearance, block slopes down to rear) around the foundations as outside is inpractical, paving, trees, neighbours drive and levels, also a few difficult people who moan about everything. I have some termite damage and want to get drainage done first before treatment - chemical barriers. Had loads of vents and a fan put in and want to fix it once and for all, if I overdo it that is better than underdoing it. Once it is drying out we move onto the next phase - termite treament.
I have an internal drain in a basement I am going to use for the final outflow of the drain (sump with automatic pump) - that part is all figured out, levels and so on.
All the hard work is done, digging - phew! - Now i know what colditz was like!
In excatvating I have found where the sewer, mains and electric supply comes in there is a large hole in the double brick about 60 cm down resting on foundations, I have excavated inside and outside, there is space all round pipes to try and seal it. This has let water in from the outside (there is evidence of this, moisture & a few mushrooms growing on the foundation shelf next to it). Before I fit the ag pipes I want to make sure this leakage is at a minimum. I did think maybe this was where the blighters were getting in, no evidence of them getting in there, that and moisture is my main concern.
My first questions is:
What is the best way to plug it, should I use concrete or acrylic render? with bondcrete mixed in to plug it from inside and outside or is there another method like expanding foam I should use? I want to get the maximum seal i can.
My other question is:
When I put the agregate in, is it ok to fill to top of trough (to where present level is) and then level out soil on top of this to about same level as outside, moisture seems to be coming in under foundations and the level inside is lower than the outside by about 30cm. My thoughts are that the moisture comes under the foundations by finding it natural level and hits the drain and will follow it's path and soil on top will make no difference, in fact will help seal in the dampness in the drain from the underfloor space - is this the way to go? I am concerend that having the inside level much lower than outside has agrivated the problem. Obviously there is a load of soil piled up that I can use, or should I say need to spread out to help with air movement, or do I leave it, the agregate, un-capped with soil and do the slog of spreading soil around to lower levels on other side of underneath the house?
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Sorry for the long drawn out explantion, I wanted to give all the facts as I see them.
I have an internal drain in a basement I am going to use for the final outflow of the drain (sump with automatic pump) - that part is all figured out, levels and so on.
All the hard work is done, digging - phew! - Now i know what colditz was like!
In excatvating I have found where the sewer, mains and electric supply comes in there is a large hole in the double brick about 60 cm down resting on foundations, I have excavated inside and outside, there is space all round pipes to try and seal it. This has let water in from the outside (there is evidence of this, moisture & a few mushrooms growing on the foundation shelf next to it). Before I fit the ag pipes I want to make sure this leakage is at a minimum. I did think maybe this was where the blighters were getting in, no evidence of them getting in there, that and moisture is my main concern.
My first questions is:
What is the best way to plug it, should I use concrete or acrylic render? with bondcrete mixed in to plug it from inside and outside or is there another method like expanding foam I should use? I want to get the maximum seal i can.
My other question is:
When I put the agregate in, is it ok to fill to top of trough (to where present level is) and then level out soil on top of this to about same level as outside, moisture seems to be coming in under foundations and the level inside is lower than the outside by about 30cm. My thoughts are that the moisture comes under the foundations by finding it natural level and hits the drain and will follow it's path and soil on top will make no difference, in fact will help seal in the dampness in the drain from the underfloor space - is this the way to go? I am concerend that having the inside level much lower than outside has agrivated the problem. Obviously there is a load of soil piled up that I can use, or should I say need to spread out to help with air movement, or do I leave it, the agregate, un-capped with soil and do the slog of spreading soil around to lower levels on other side of underneath the house?
-------
Sorry for the long drawn out explantion, I wanted to give all the facts as I see them.