Buying house with Basement - damp issues?

DIYhelp76

Hi

A relative is thinking about buying a Victorian mid terrace house (2 bedroom) which has a basement. The basement is unconverted and just used for storage. It isn't heated and just has gas meter and utility pipes. When entering it does smell a bit of damp but it is unheated.

They wouldn't necessarily want to convert it to living space immediately but it might be an option later on. For now, what considerations are there when buying a basement? What's best way to check it won't cause damp problems with the rest of structure of the house?

It's quite a small basement room, around the size of a small double room and accessed from a flight of stairs down from the hallway.

A call to the Council makes it sound expensive to convert as they say it would need an escape route window and stairs, damp proofing/tanking and building regs consent.

Any thoughts/advice very welcome.

Many thx in advance.

AdrianC

The water table is the main issue. You dig a hole down into the water table, you're going to have water ingress unless you do some serious work to stop it.

As far as the rest of the house goes, you're below the DPC, obviously. The basement's not that different to the foundations - you just need to think about how not to bridge across the DPC.

FreeBear

DIYhelp76 wrote: »

They wouldn't necessarily want to convert it to living space immediately but it might be an option later on. For now, what considerations are there when buying a basement? What's best way to check it won't cause damp problems with the rest of structure of the house?

Converting a cellar in to a usable living space rarely works. Use the space as it was intended - Storage for root crops, coal, wine & beer.

Keep the space well ventilated, and if there is a sump pump down there, make sure it is serviced regularly. That should minimise any potential problems with damp.

G_M

As the council says,conversion will be costly, both to comply with building regs, and to manage the damp issue.


Basements by definition are below ground level, so get damp. Nothing wrong with that at all. Unless/until you want tomake them a bedroom!

Cakeguts

Don't buy a house thinking that you can convert the basement. It will cost more than you could ever get back if you needed to sell it. If the house isn't big enough without converting the basement then they need to look for something larger.

Mutton_Geoff

Cakeguts wrote: »

Don't buy a house thinking that you can convert the basement. It will cost more than you could ever get back if you needed to sell it. If the house isn't big enough without converting the basement then they need to look for something larger.

The only exception to this is in London where £psf is so high that it makes it viable. Everywhere else, forget it.

Doozergirl

Mutton_Geoff wrote: »

The only exception to this is in London where £psf is so high that it makes it viable. Everywhere else, forget it.

Even then it's because of the lack of space to go up or out, as both are cheaper and easier to do. Or they do the basement as well

DIYhelp76

Hi

Many thanks for the helpful replies.

They weren't looking for a house with a basement, it's just that this came up. It is useful storage space as it is and the costs of conversion sound prohibitive anyway.

They are just now worried about the pros and cons of buying a house with a basement in it, mainly as regards risk of damp/structural defects to main house.

It's a Victorian terrace and assume the basement was original.

What is a "sump pump"? If it isn't there, would it need to be installed? Trying not to buy something which is going to end up having problems or lots of extra expense.

There is a window and at the ground level outside at the front there's a kind of plastic cover thing with earth and plants growing in it, if that makes sense?

There's no heating - should/must this be added?

Is insurance etc likely to be more expensive/difficult to get?

The gas meter is stored down there and the pipe on it is a bit rusty coloured, maybe caused by the damp. Is this all too much of a worry to take on?

AdrianC

DIYhelp76 wrote: »

They are just now worried about the pros and cons of buying a house with a basement in it, mainly as regards risk of damp/structural defects to main house.

It's a Victorian terrace and assume the basement was original.

Exactly. The basement hasn't caused any problems in a century and a half or so. Why would it now?

What is a "sump pump"?

It's a pump to remove water from the lowest point in the basement. Water likes obeying gravity. You make a small recess in the floor - a sump - and put a pump there to get shot of water that collects there.

If it isn't there, would it need to be installed?

It hasn't needed one thus far.

But - and this is the key - everybody thus far has regarded it as exactly what it is (a cellar) and not what it isn't (extra living space).

...at the ground level outside at the front there's a kind of plastic cover thing with earth and plants growing in it, if that makes sense?

Not really. Unless it was an original cellar hatch to enable coal to be delivered easily.

Doozergirl

There's no additional risk with a basement. It's a bonus from a structural point of view because you can see the bones of the building and keep it all in good condition.

The rusty gas pipe could be a bit of an issue but it's not a big deal or an expensive job to replace it if it is required.

A sump pump would be needed if it floods. Some cellars do, many don't. The water needs a bit of help to escape. You can have a pump that works automatically if it is submerged. It's perfectly normal, you just don't want the water to sit around for long as the humidity will increase, obviously.

The best advice is not to mess around with them, don't try to tank it in a half hearted attempt to create 'dry' storage. It isn't.

coffeehound

It's worth making sure the vents to the street are built up an inch or so to stop rainwater entering; it's surprising how many housholds haven't done this.

Also since humid air rises, a PIV fan in the loft would counter this by forcing air downwards and out through the basement ventilation. The door to the basement would need a grille or gap under the door to allow this.

One house I rented had the laundry machines in the basement, raised off the floor, which worked fine.