J.A.S.'s fixing the damp & swimming pool in the house thread....

John_Pierpoint

Have you crawled down there, is the surface (under the water?) concrete or earth?
Every time the water evaporates it leaves behind a deposit of "salts".
Unfortunately these salts can be hygroscopic, if not deliquescent, and the problem is getting worse over time.

http://en.wikipedia.org/wiki/Hygroscopy

You really do need to dry out that underfloor space and get rid of the salts sucked into the internal plaster.

Is it possible to drain that underfloor space, without resorting to (ideally) two pumps.

If the dampness spreads into the timbers embedded in the walls, if it has not done so already, you will be risking getting dry rot even if the timbers have been spayed with rot & woodworm "proofer".

cyclonebri1

JustAnotherSaver wrote: »

Update time. & from reading your two posts there, this guy seems to be in the area of being correct.

Now you'll have grasped by now i don't know anything about this, so i swallow what i'm told. I'm more comfortable with what the independent survey fella said today than what Peter Cox told me the other week...
...although to be fair, the independent chap was able to look under the floorboards whereas Peter Cox wasn't (due to carpet still down). Would PC have concluded differently? Maybe, maybe not.

I'll need to note this down before i forget any more than i already have....

* You guys are right (or at least this independent chap agrees with you), the water under the boards IS the cause of the walls being as they are.
* Obviously he can see the pump better than that photo shows you guys, but he says it shouldn't have crud all around it & it should be in its own bucket. He says we need to check to see if it's working (how?) but a new one is cheap enough (£50 +/-). As for requiring to be deeper, the floor is fairly level & you can see where it's been dug out to house the pump, so it's already under the level floor. I know nothing about this but i don't see why it'd need to be deeper still..??

* He could smell the damp in the air, i couldn't, but then he knows what he's smelling.
* He did talk about the water making the air moist (or something to that effect - on the lines of what you said). So while the DPC will stop the damp penetrating the brickwork from the bottom, it doesn't stop the moisture all around due to the lake there getting above the DPC level & this in turn then rises through the wall. So while the DPC will be doing its job, it can't solve everything.
* He says we need ventilation under there. Good air flow. I asked what & he said air bricks to channel air under there. Ideally piping running all the way through from the air brick rather than just an air brick placed at the front of the house. He said the concrete flooring in the extension at the end of the living room wont help.
* He did say drilling through the party wall to help with airflow is another possibility (regards helping airflow), but said that this is pretty much very naughty.
* He talked about the use of cavity trays & weep vents in the extension, of which i have forgotten. I do remember he said the weep vents can block. He also said builders can be very slapdash & take shortcuts & not bother.

* The wall that separates the living room & hall may well need doing. He said the plaster may be newer than the party wall & in time it will go the same way. It depends how pro-active we want to be as to whether we sort that too.
* As we all have agreed - he said whoever did the drive is a bloody numpty (regards the air bricks) & that we really need to sort that by way of ACO channeling ASAP.
* He said we should/could remove a brick on the side of the house (how?) to see if the cavity walling has collected crap at its base, which will trap moisture. If clean then joy. If not then it'll need pulling out & the cavity walling made good again.

* He didn't seem to be a fan of chemical solutions & as already said, neither am i. I much prefer the idea of something physical.

On to that came one possible solution....

* He suggested studded plastic sheeting for the walls & then plasterboarding on to this. He said if you go the chemical route, it's just delaying the inevitable because you're not solving the problem (under the boards). The dado rail & indeed all woodwork (minus floor boards) will need to be removed (no problem). Down side here is it will jut out & so the sockets will need looking at, the coving will need looking at & the fire surround will need to come off. The hearth should also get levelled out he said as it slopes backwards.
* He said the plastic sheeting membrane & plasterboard approach will stop the damp effecting your decorating. If we ever sold then a damp meter would never pick up damp & the wall is going to do whatever it's going to do. We could chip away at the plaster first or leave it as is. He suggested leaving as is as it gives a level surface to begin with & no point in creating needless work.

* Regards the lake underneath, one solution he gave was filling with limestone to the highest point it will ever reach & then putting visqueen with bricks on top on top of the limestone. He did say that there's a gap between the boards & limestone but i forget the distance. 6 inch comes to mind but this could be for something else. He said if we don't limestone high enough then this could end up being disastrous. That's just one idea.

* He said regards the sump pump - one problem with this is it can also remove bits of the soil with it, which can then result in movement. Bit worrying, but then what do you do?!

And i'm afraid that is as much as i can remember right now. He's going to do his report & email it.

Whether he is dead on the money or not i don't know, as i don't know this game. I am however more comfortable with the outcome of this visit than i was with the Peter Cox visit.

I think you have found the guy to help you, :T, the bold bit is the only thing I disagree with, provided the sump is not adjacent to a wall any trace silt removed will not affect foundations

Should the sump be deeper?, the deeper and bigger in area the better in my view. By that I mean maybe 300mm deeper and 600mm square.
A crate wrapped in permeable fabric takes care of most silt.

The bit the previous poster added about the base is valid, but I'm pretty certain it isn't going to be concrete in any form.


Dead on the money?, I think he's pretty close;);)

JustAnotherSaver

John_Pierpoint wrote: »

Have you crawled down there, is the surface (under the water?) concrete or earth?
Every time the water evaporates it leaves behind a deposit of "salts".
Unfortunately these salts can be hygroscopic, if not deliquescent, and the problem is getting worse over time.

http://en.wikipedia.org/wiki/Hygroscopy

You really do need to dry out that underfloor space and get rid of the salts sucked into the internal plaster.

Is it possible to drain that underfloor space, without resorting to (ideally) two pumps.

If the dampness spreads into the timbers embedded in the walls, if it has not done so already, you will be risking getting dry rot even if the timbers have been spayed with rot & woodworm "proofer".

Arrrrgh, this is become a right old headache.

Out of interest, should any of this have been picked up in any search/survey?
We went for homebuyers survey. If we'd spent the extra on structural, should that have picked it up? I know it's all a little late, but just out of interest.

No we haven't gone under the boards. For one the hole is too small for me for two i don't have any wellies, for three i don't have a stick at the house yet to have a dip & scrape.

Is it possible to drain it? Well, i guess anything is possible. Question is how??

Do we get down there with some sandcastle buckets & scoop & chuck? Extremely time consuming & not very ideal. Scoop up the water, pass up, next person takes it to a drain outside & chucks ... and repeat (1000+ times).
Problem then is ........ when the water returns. You can't keep scooping & chucking all the time.


Regards the sump pump ..... who fits these things? Is it a plumber you'd see? Builder? I know i'm coming across as dim now but this is all totally new to us. For the sake of £50 (if the guy is right) i'd be inclined to just buy a new one. That way it's new & you know it works. The old one looks cruddy & nobody knows how old it is or if it works.

Then there's the air brick situation & air flow. Is it likely to make THAT much of a difference? There's already 2 air bricks under the living room window. There's 1 in front of the hall & 1 at the side of the hall.

He stuck his meter reader into the floor beams & the base, although it felt dry, it read something like 26% i think he said. It was 20something. 24%-26%. I think (there goes the memory again) he said this could be due to the moist air around the beams as opposed to the water level actually touching it physically.

get rid of the salts sucked into the internal plaster

How'd you do that? Are we on about around the dado rail?

I guess this is not necessarily where you & this fella disagree, but where you're not keen on his suggestion of putting the studded plastic sheeting on top of the wall as it currently stands & leave the wall as is?
I think you're talking about chipping away at the plaster & re-plastering & then putting on the sheeting & plasterboard he suggests, but only after chipping away at the old plaster.

Or are you talking about the brick wall under the floorboards?

I have just remembered he did talk about dry wall adhesive at some point, but not standard stuff - waterproof dry wall adhesive instead. I can't remember what he mentioned this in reference to but we were talking about the sheeting & plasterboard around the time he mentioned it.
There was something else he mentioned in connection with that by my memory is lacking again.

JustAnotherSaver

cyclonebri1 wrote: »

I think you have found the guy to help you, :T, the bold bit is the only thing I disagree with, provided the sump is not adjacent to a wall any trace silt removed will not affect foundations

I must admit that i am happy with what this guy told me. Peter Cox salesman came out with a lot of big words & fancy science & said you need XYZ.
This guy just said, this is the cause, this is what it's doing, this is what you need to do, but it isn't just the wall that needs sorting. You can do this, or you can go this far, or you can go even further. Depending on requirements & money.

As for the sump pump .... it's a few feet away from the front of the house (bay window).

Should the sump be deeper?, the deeper and bigger in area the better in my view. By that I mean maybe 300mm deeper and 600mm square.

I'd guess that it is perhaps 600mm square. Not sure about 300mm deep. Maybe it is. It's hard to tell without measuring. I'm just imagining a 2x2 flag for the 600mm & i'd say it's about that. Depth is harder to tell.


It's difficult to see from the small hole we have, but where is this pump likely to drain the water to? Just the drain outside somewhere?


Also, how much water 'needs' to disappear from below? I imagine the pump has to sit in a certain level of water, so maybe not every last drop & then bone dried out .... but to what level? As i say it's perhaps 1 course of brick high at the moment. So, 65mm-ish (without a stick to tell you for sure).

fluffymuffy

Can we have a photo of the outside of your house round the back? I'm interested in the ground level in relation to your dpc, and (of course) any/all air bricks.

You mention an extension - does this cover some air bricks? Is it on the back? Is it of solid floor construction?

JustAnotherSaver

fluffymuffy wrote: »

Can we have a photo of the outside of your house round the back? I'm interested in the ground level in relation to your dpc, and (of course) any/all air bricks.

You mention an extension - does this cover some air bricks? Is it on the back? Is it of solid floor construction?

I'll have a doosy-do tomorrow for you.

TBH i'm not sure where the DPC is, so i don't know where the ground level is in relation to it.

I couldn't tell you if the extension covers air bricks or not. I imagine it probably would because there's air bricks to the front of the house & air bricks to the side, so it would only make sense therefore that air bricks would have also been to the rear.

The extension is at the back of the house, yes and it is of solid floor construction. The chap informed us that the extension is not damp, however what was the old external wall (the side of the wall that would've taken the rain before the extension was built) is showing damp. I think this could've been at the point he talked about cavity trays & weep vents but i've forgotten what he said.

The extension, if it helps (regards regs at the time) was built in 2000 IIRC.


Slightly off topic, but there's moss growing on top of the extension roof. Now, i don't want to risk climbing out of the bedroom window, getting on the roof only to find it's not going to take someones weight. How do you maintain the rood if you're unsure about getting on it? Just like a garden hoe or something to get rid of the moss?

To look on the positive side, at least i'm learning stuff all the time having bought this house :rotfl:

EDIT: From doing a little reading on sump pumps, i have found that:

1) It's best to have 2 installed & not 1 as in our case - for the obvious reason of what if one fails.
2) Good idea to have an alarm system in place telling you if the thing has failed
3) The guy was being very conservative with £50.

Also from looking at YouTube videos, i would say that our pump has failed. The fact it is all totally submerged & what i suspect is the float is just feeling sorry for itself, i'd say it needs renewing.

fluffymuffy

JustAnotherSaver wrote: »

Slightly off topic, but there's moss growing on top of the extension roof. Now, i don't want to risk climbing out of the bedroom window, getting on the roof only to find it's not going to take someones weight. How do you maintain the rood if you're unsure about getting on it? Just like a garden hoe or something to get rid of the moss?

Nothing wrong with a bit of moss. Leave it alone.

JustAnotherSaver

fluffymuffy wrote: »

Nothing wrong with a bit of moss. Leave it alone.

Ah i see. We were only going off what the survey said.

I like how they say moss needs looking at, but there's a failure to mention all this water under the house which appears to be common [local] knowledge.

fluffymuffy

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Do you know what the mysterious pipe is in the top right hand corner of the brickwork in this photo? Is it connected to you rainwater pipe? (joke). I do wonder what it is though. It looks to be made of asbestos (?).

Just below it the joists have a white fillamenty look to them. I'd be alarmed this might be the beginnings of dry rot. Watch your airbricks for signs of brick-red "dust" coming out.

JustAnotherSaver

We have some guarantee paperwork but it's just not readable. It lists under the contract details:
* Woodworm/Wood Rot
* Rising Damp
* Replastering

With a 30year assured guarantee. This was from work done in 1991, but as i say, it's worthless as we really can't read anything off it as it's just a poor faxed copy dated 1999 (when the previous owners bought the house).

I have no idea what that pipe work is. That wall is in the centre of the room ... there's a bit of distance to the right before you even get to the party wall, so i'm not sure about that pipe at all.

I did have an idea about getting the water out....

I'm guessing the sump pump is knackered due to the level. Am i right in thinking it's a plumber we see to rectify that (installing a new one)?

That aside, renting a pump from a tool hire shop (i know the owner - he wont give me it for free, but possibly reduced price). Stick one end in where the sump pump is, sucks it through the motor & pumps it out the other end .... just feed that end out of the window or something, or maybe out the front door if it's long enough.

My employer borrows it when the drains get blocked & it doesn't half suck some juice. Depending on how long the hose end is & whether it'll reach out the front door, it'll suck the majority out of there in no time.