Water ingress in crawl space

[youkiddingme]

We have a bungalow with a crawl space and clear evidence of water ingress, though not to flooding depth. It is however leaching lime from the mortar and salt from the bricks. There is evidence of pointing needing replacing but the walls are damp. So far the timbers remain dry and in good order.
I'd really like to get someone out to have a look and advise us on how the water is getting in - I've already had cameras down nearby pipework and ruled those out, and what if any remedial action we need to take.

I've tried damp companies who say ask a structural engineer, and structural engineers who say ask a damp company. Access is a little difficult, though both myself and my hubby have been down there - it's not a 'suited and booted walkaround. It may well be nobody wants the job - it seems whatever work we want doing lately, trademen are cherry-picking the easy payoffs.

I have thought about using a combination of pea shingle and damp membranes to line the base to reduce moisture levels then repointing the brickwork. Not sure if this would fix it, though.

Any advice welcome.

@youkiddingme

What is a crawl space? Where is it? What part of the property? Water can come from many sources.

It could just be ground water. Is it coming up into the house? maybe just add a few more airbricks? I wouldn't be worrying too much about damp in the crawlspace unless it was affecting inside the house, one of the points of crawlspaces is for airflow to help prevent any damp issues.

I'm no expert, but I'd start off by finding out where the water is coming from. As Otters has suggested, it could be groundwater. On the other hand, it could be rain overflowing the gutters.

There's a YouTube channel that I watch - the guy is based in America - called Gate City Foundation Drainage. He has lots of videos about basement flooding, which you might find interesting.

I would think that what you need is a drainage company because, wherever the water is coming from, it needs to be channelled to somewhere other than your crawl space.

How deep is the crawl space ? Ive been in a few that sound like yours and most of them smell a bit musty as they are under the damp course. More so in wetter weather. As long as the floor is dry and there is no damp above the damp course then I wouldn’t worry too much . Just make sure there is good airflow under there to prevent any condensation.

There seems to be adequate ventilation and the suspended timber floors above the crawl space appear dry. My concern is the very high humidity down there - we're currently running dehumidifiers but that's expensive and the fact that so much lime is leaching from the mortar that I'm worried about the integrity of the brickwork over a longer period of time. I can see there's some pointing could do with doing but I'm not sure how well it will dry if the walls are so damp. The water is basically coming through the bottom of the front wall, not to any depth, but enough to create and almost permanent wet patch at the base and to keep the bricks very damp.

Bricks being. Wet / damp permanently is not an issue, a lot of houses especially old ones have brickwork under the ground level that are wet and never dry out . It doesn’t affect them in any way.

When we were building our extension we uncovered old foundations from a building that was there before the house was built. When the bricks were removed most of them were still as good as new a few had cracked in half but none of them had any wear on them. They could have easily been reused with the mortar cleaned off.

So this is the void under your floor?

High ground water after all the rain?

Wet bricks can spall and get mould on them. Timber can get wet rot or fail. As can the bricks if they are structural.

You could get the area tanked. Damp will affect the floorboards. Has dpc failed? Could ground around house be too saturated and it's causing excess moisture? Houses dry out and get damp again with the weather.

Brickwork spalling is caused by the bricks being wet and then followed by freezing temperatures ,which then expends the moisture in them and causes the bricks to crack. This is why you see a lot of brickwork on garden walls damaged as they get wetter and a lot colder than bricks on houses ( no roof or heat coming through them ) Some bricks are frost proof to prevent this.

Wet bricks underground don’t get any frost on them ,so no wear. Its the weather that wears/ erodes brickwork ( driving rain, frost ) chimney stacks tend to suffer erosion the most as they get the worst of the weather.

Some bricks with a high salt content will wear on the face due to being wet all the time and the efflorescence ( salts ) coning out. Its unsightly but wont affect its strength

As long as there are no signs of damp/ moisture above the damp course or the suspended floor then sounds like there nothing to worry about.

The key is good airflow under there , it should be the same temperature as outside so no condensation can form on the timbers. It sounds like you have that. Turn the dehumidifiers off and see what happens over the summer.

Yes there's a void under the entire bungalow below ground level but not the height of a basement. Access is via small doors you have to crawl through, then you have to walk bent double. It's to access pipes and wiring. The dampproof membrane for the house is a at head height in the crawl space. The timbers, which support suspended wood flooring seem to be sound and dry - tested ok with meter. But the brickwork in places is wet.

The issue is how to fix it or who can advise us. So far nobody we have contacted - damp experts or structural engineers have been interested in coming to look.

Hi,

did you find the cause of the problem?