Advice for water drainage around my cottage to prevent damp

[Anneliese]

Hi everyone - I have posted before about my lovely cottage but I have another question for you all.

My cottage was built mid 1800s. When we bought the cottage we didnt have a survey done (against my better judgement). Around the outside of the house concrete has been laid right up to the side of the house and there has been an issue with damp at skirting board level in the past.

Now the thaw is happening I have noticed the rain water is collecting on the path and not draining away.

I would like to solve the drainage...possibly digging up the concrete and laying a gravel border. Would this help?

I am not sure what the foundations are like (or if there are any) nor what the DPC is. Would putting in this gravel for drainage be a help or hinderance to the cottage. I am not at all clued up on building work so any advice would be greatly appreciated.

Anneliese

 

[stuart45]

I am not sure what the foundations are like (or if there are any) nor what the DPC is.
Anneliese

Unlikey to have decent foundations or any DPC. They relied on lime mortar to allow movement in the walls and the lime plaster allowed the walls to breathe the damp away.

 

[Anneliese]

Thank you for that Stuart. I thought that may be the case .....do you think that by digging up the concrete path around the house and replacing it with gravel would help with the issue of drainage and damp or is it a fore gone conclusion that damp will get into the bricks from under the house due to lack of decent foundations and dpc?

 

[merlin50]

i have an old cottage gravel one side and flower beds the other, no damp problem, no foundations or damp proof. i would get rid of the concrete

 

[stuart45]

If the water is sitting on the path against the walls, then the levels are wrong and the path would be better taken up. Gravel is the principle of a French drain and helps with drainage.

 

[Anneliese]

Thank you again Stuart...sounds like a plan to me...there are drains in place but the water doesn't flow into them.

Cheers

 

[r896neo]

Don't be tempted to go the easy route and just cut a channel next to the house to install a french drain. Beecause an old cottage will likely have shallow or very little in the way of foundations directing water along the side of the base of the walls would be a bad idea.

As mentioned before it's probably best to dig up all the concrete.

 

[Anneliese]

Thank you for the reply. I was thinking of taking up all the concrete all the way round the house. Do you have any suggestions as to how deep to dig once the concrete is up or is it simply a matter of replacing the concrete with gravel. Would the lack of concrete around the house make it more unstable and prone to moving if it isn't sat on proper foundations?

 

[stuart45]

Gravel on it's own would not make a French drain, and the water would normally soak downwards. There are different methods of construction, one being the lining of the trench with a membrane to prevent any water reaching the footings.
However the trench can't go below the bottom of the foundation.
Another option would be to re-lay the concrete to the correct levels into the existing drains, or away from the house.
The house was probably first constructed with earth against the walls.

 

[r896neo]

whilst its a bit of a headache, the best bet might be to dig a test hole in an inconspicuous area behind/ to the side of the house which will tell you roughly how deep the concrete is and what you might have in the way of footings.

Simply removing the concrete will improve the drainage a fair bit and that would be the first step to see if that changes anything. then you could consider some arangment of french drains or re-instating paving/ concrete with a correct fall away from the building.

 

[Anneliese]

Thank you so much for your help in this matter...must admit the thought of damp taking hold yet again, which there are signs already even though it was replastered about a year ago, is quite scary.

Shall have to go and get a pneumatic drill next lol.

 

[noseall]

Finding damp in masonry is not always the result of external surface rainwater.

You need to explore all potential causes before jumping to conclusions though the obvious is the best place to start.

 

[Anneliese]

Thank you for your reply - I am open to all trains of thought on this but I am purely basing my thoughts on the fact that the damp plaster seems to be in places where the concrete is higher than the internal floor level or where the is a crack in the concrete externally. If digging up the concrete and lowering the external floor level and replacing with gravel doesnt help things I will have to look into it further.


Thanks again