Preventing my garden draining into my foundations

[Adsibob]

5 hours ago, Andy H said:

Its reassuring to hear your surveyor comments. Its quite surprising that a structural engineer would not know, given your location it couldnt be a water table problem!

 

Thanks   Andy

Yes, but this structural engineer also wanted me to inject my foundation bricks with a chemical DPC. He's a great structural engineer, but not sure I'd follow his advice on other matters!

[SuperJohnG]

On 30/01/2021 at 18:44, joe90 said:

 You could always do like I did and run the drainage pipe into you’re drains, that’s where the rain from the roof goes!!!

This is exactly what I'm doing right now....I have 110mm twinwall land drain which I've just laid and added tees where the downpipes will drop in later on and then the whole lot discharges onto the burn. 

 

Few pics....and also the swimming pool at one end of my foundations (which no longer exists thanks to the drains. )

[Andy H]

On 31/01/2021 at 17:21, Russell griffiths said:

Have you considered digging a bigger hole and having a low retaining wall instead of having to waterproof your building walls

i did this on a garage that had a height restriction. 

Thanks Russell

 

I had considered a low retaining wall and then building within it but as I am already at the neighbouring boundaries it would mean I would have to reduce the size of the building which I would prefer not to do. It would however mean the building would be far less suceptable to water / damp penetratioI. I costed it out at around £12k  and this combined with a smaller building makes me reluctant to go down this route.

 

I spoke with one of the technical people at NSBRC and their suggestion was to backfill with waterproof concrete which would also act as a retaining wall and prevent the need and cost of formwork whilst maintaining the maximum building size. I would be interested to hear other peoples views on this.

 

Andy

[Andy H]

On 31/01/2021 at 23:41, SuperJohnG said:

This is exactly what I'm doing right now....I have 110mm twinwall land drain which I've just laid and added tees where the downpipes will drop in later on and then the whole lot discharges onto the burn. 

 

Few pics....and also the swimming pool at one end of my foundations (which no longer exists thanks to the drains. )

Thanks for the photos - are you in effect building french drains in the land surrounding the proposed building?

 

A friend of mine suggested that I build a french drain system in my garden directing any rainwater from the garden ever getting around my building in the first place. It sounded like a good idea. I could try and do something similar at my neighbouring boundaries to restrict the rainwater running from their garden into the backfill around the building.

[SuperJohnG]

19 minutes ago, Andy H said:

Thanks for the photos - are you in effect building french drains in the land surrounding the proposed building?

 

Yes. Its just a land drain around the full perimeter of the house footprint, its required in my foundation systems drawings that there is a perimeter (french) drain minimum 500mm outside the edge if my insulated foundation. The footprint is now essentially an island. It just ensures and water can free drain and there's no possibility of frost heave. 

[Andy H]

54 minutes ago, Andy H said:

Thanks for the photos - are you in effect building french drains in the land surrounding the proposed building?

 

A friend of mine suggested that I build a french drain system in my garden directing any rainwater from the garden ever getting around my building in the first place. It sounded like a good idea. I could try and do something similar at my neighbouring boundaries to restrict the rainwater running from their garden into the backfill around the building.

This link explains how to drain the garden https://www.jdpipes.co.uk/knowledge/land-drainage/basic-guide-to-land-drain.html. I think I will do this in addition to the drainage and sump pump around the foundation mentioned by @joe90

Edited February 2, 2021 by Andy H
correct typing error

[joe90]

7 minutes ago, Andy H said:

think I will do this in addition to the drainage and sump pump around the foundation mentioned by @joe90

The sump pump is only required till the foundations are poured, then French drain can be installed as the ground is built up around them. Mine is strip foundations, @SuperJohnG is a raft.

Edited February 2, 2021 by joe90

[Andy H]

9 hours ago, joe90 said:

The sump pump is only required till the foundations are poured, then French drain can be installed as the ground is built up around them. Mine is strip foundations, @SuperJohnG is a raft.

Lucky you!

 

I mistakingly thought you had a structure / part structure underground - mine will have to be a permenant fixture☹️