Mixed recommendations regarding basement damp proofing

[pb2012]

Hi all,

I have a basement all opened up and in the stages of becoming a living/kitchen/dining area.

One half of it is all good, the other half needs damp proofing. I've been getting mixed recommendations from damp proofers and am looking for experiences and opinions on the matter!

The primary options are:

1) coat brick walls internally with tanking slurry/bitumen, tied in to the DPM of the floor. batten walls, insulate and board over + skim.

2) line walls with breathable membrane (the bubble wrap type stuff), sealing all joints etc. Then either dot and dab straight on, or batten and board.

The basement is about 70% below the outside floor level if that makes a difference.

The breathable DPM solution sounds solid, but the guy advocating taking generally filled me with more confidence and seemed very knowledgeable.

Has anyone done both in the past, or have experience with basement damp proofing?

Any opinions are most welcome.

Cheers.

 

[KenGMac]

philb2012, Good evening.

Suggest you await more information from board contributors.

But? how about you ask both suppliers to have them contact at least two previous clients and if poss go and see and more especially talk to the "Clients"

How about a Google search of each company, or use social media to see if there are any adverse notifications as regards the companies.

Ken

 

[^woody^]

The waterproofing should be designed to BS 8102, and no other quack damproofing scheme will do.

If it helps, all primary wall and floor waterproofing will fail. No matter what it is and how good you are told it will be done, it will fail. This will be due to the installation (no-one and achieve 100% quality) or design (a crap design or wrong solution), and not the materials. The only differing factor is when. Even the best systems can last as little as the guarantee you get - 10, 15 years?

To deal with this simple fact, a secondary precaution is taken and this is a drained cavity an a sump pump.

You need building regs approval too.

 

[pb2012]

The waterproofing should be designed to BS 8102, and no other quack damproofing scheme will do.

If it helps, all primary wall and floor waterproofing will fail. No matter what it is and how good you are told it will be done, it will fail. This will be due to the installation (no-one and achieve 100% quality) or design (a crap design or wrong solution), and not the materials. The only differing factor is when. Even the best systems can last as little as the guarantee you get - 10, 15 years?

To deal with this simple fact, a secondary precaution is taken and this is a drained cavity an a sump pump.

You need building regs approval too.

I would hope that if a room is effectively wrapped in plastic then water won't make it's way in, but I suppose it always finds a way.

Can a sump pump be realistically relied upon to work and be effective after 15 years? It's a mechanical electrical device right, so I'd be weary of that that too. The quotes I've had to install a pump, run a gully and drain out any water are quite prohibitive.

 

[^woody^]

I would hope that if a room is effectively wrapped in plastic then water won't make it's way in

And the bloke doing it has had a barney with his missus the night before so is in a bit of a mood and can't be that bothered with your basement because it will be a few years before you find out he has not sealed the joints properly. Or he lets the apprentice have a go, or ......

You can't guarantee "effectively wrapped". No-one can. It will leak - that's the only guarantee you will get, no matter how good the salesman's patter.

Pumps will work, they are not on 24/7. And are easy to fix if they don't. The better systems have two pumps, where one is a back up or each used alternatively, and each has a failure alarm and self test mode.

How do you gauge "prohibitively expensive"? How much is the basement and contents? How much will one cost to retro fit once the penny drops? Who will buy a house with an unknown system and no pump?

Decisions, decisions.

 

[KenGMac]

OK I must admit I am skeptical about retro applied Damp proofing.

If you consider it, the natural ground water which will rise and fall will be there forever.

Some sort of all singing all dancing new fangled next generation internally applied DPM will at some point in the future fail probably well within the makers guarantee period, by which time the vendor has morphed into some other name, product and that is what happens, the so called "Guarantees" have so many get out clauses it makes an insurance policy look like a good deal???

As Woody above keep it simple yes sump pumps with a float trigger work.

Hence my O/Post suggesting investigation on Google and Social Media ?

Ken

 

[pb2012]

A pump for added peace of mind would of course be great, but it's one to really think about. The basement clearly has moisture penetrating the floor and walls, but it's over 100 years old. There hasn't actually been any water pooling anywhere, even after all this time.

I guess it's hard to advise without being able to inspect the site.

There is a natural slope in the basement floor leading to the front external wall face. This is where the damp is most concentrated and where a natural place for a drainage channel is. I need to weigh up costs here and probably chat with a couple more contractors.

Google isn't really turning much up in terms of reviews etc. I might ask about a few past client testimonials though.

 

[wessex101]

Cavity drain (I assume that's what you mean by "bubble wrap") every time. They are far more robust than the slurries and do not suffer from hydrostatic pressure which usually causes the painted on products to fail.