House smells like wet concrete

(14 Posts)
1984isnow Fri 07-Aug-20 08:41:25

Occasionally I have noticed that downstairs smells like wet brick/concrete, usually when it has rained lightly. When we had weeks of heavy rain, I didn't notice it at all. Yesterday i think it rained a little, and for the first time I also noticed the smell in one of the bedrooms.

There are no visible leaks anywhere, and I regularly move furniture out for hoovering etc, so I know there are no wet patches or mould behind the sofa or that sort of thing.
I have recently rejigged the bedroom so nothing behind the wardrobes.

My windows and back door are open all day, so the house is aired out.

It's not really a 'leak' smell, if that makes sense, and it's not stronger in any particular area, as you'd expect with a leak.
Very hard to explain. I thought it could be water seeping in around some old pvc windows, but when we had heavy rain I would have expected it to be worse but there was nothing.

Could it just be the smell of drying bricks, coming in from the outside? Is there any way I can figure out what it is?

OP’s posts: |
1984isnow Fri 07-Aug-20 08:46:19

Sorry, maybe I should say. My living room and bedroom all back on to the garden, and the windows are on this side.

Bathroom is on the front side of the house, never notice it here. I can't say I've noticed it in the kitchen, whether the back door is open or not.

OP’s posts: |
user1471528245 Fri 07-Aug-20 08:54:00

Is it a timber framed house? ie the outside is brick but internals are wood and plasterboard with a plastic membrane between, (most new builds, especially the cheaper end of the market, are built like this, I had a porch on mine and the water came in and ran down the inner brick work, never any issue on the inside, no stains or damp patch Just a damp smell after it had rained, also check any lead flashing such as around a chimney stack or where you have a roof join and check any guttering to make sure water is not running down any outside walls

PigletJohn Fri 07-Aug-20 08:58:51


How old is the house

Is there concrete or paving round it

Post photos of the drains, downpipes, gutters and paving please

And the bottoms of the walls, indicating where the DPC is in relation to ground level.

1984isnow Fri 07-Aug-20 13:19:17

It is a 1950s ex council mid terrace. I couldn't really tell you if it is a timber frame. Is there a way to tell just by looking?

Concrete slabs in both the back and front, but there is a run of what looks like solid concrete along the back of the house, about 0.5m width and the length of the house.

The patio slabs look like they were a diy job by the previous owners (they bought it long before the council did any upgrades). Large 900x600 which have cracked and sunken in various places. We are finding that much of the house has been a bodge job, which isn't noticeable until we begin replacing/upgrading things. So it's very hard to know what this smell could be.

There is one drain connected to the kitchen, however this is in the back porch. Porch is wooden with a slanted perspex roof and there is no smell in the porch or kitchen.

The other drain is connected to a brickshed with and old loo in it (which we don't use) but I'm not sure if this would feed into the main house too?

The black bricks, I am pretty sure are the last two rows, however I remember noticing that the row of concrete against the house is slightly higher than the bottom set of bricks in that makes sense? I will get some pics later.

If this was due to a leak caused by rain, would it be more noticeable during heavy constant rain? As there's no smell at all when it does rain for longer periods, even when the weather dries up.

If it was roof related, would the smell start or be stronger upstairs?

OP’s posts: |
1984isnow Fri 07-Aug-20 13:26:53

Something else worth noting, a couple of years ago, there was a slight drip from the radiator pipe in the hallway. We had this replaced, no noticeable further leaks. We also had the all of the radiators replaced along with the pipes that come out of the floor, and the valves etc.

However, I am now thinking whether there might be an actual issue with pipework? I don't know if CH pipes would run under the floor in all areas, but the smell is the closer you get to floor level. I am not sure if that would be an intermittent smell though.

OP’s posts: |
PigletJohn Fri 07-Aug-20 13:56:45

The sunken slabs are of particular interest, especially if they are close to the house or a drain. The photos will be very useful.

Are some of the internal floors concrete?


1984isnow Fri 07-Aug-20 14:31:16

I've a lot of pics on my phone I've sent out for quotes so going through to see if there is anything useful before I have a chance to take more. I've zoomed in on this one, hopefully it is of use.

I never took notice of the vent. I've had a quick google and it looks like it should be higher from other pictures. Could that be a cause?

The sunken slabs aren't near drains and they are about 4m away from the house, i think its just uneven soil. It looks like they started breaking them up to make crazy paving then gave up in the end and laid the rest as whole pieces.

Similar was done at the back of the garden, a small patio but the slabs were just 'placed' on the lawn, rather than laid.

I am assuming the kitchen is concrete, we havent replaced yet but based on similar houses. The rest are floorboards.

OP’s posts: |
PigletJohn Fri 07-Aug-20 16:21:56

your picture shows an airbrick that is lower than the paving. This shows that the ground level has been raised since the house was built. It's a common mistake by incompetent buffoons.

The airbrick is supposed to let air flow through the space under your floorboards to carry away any water vapour and keep them dry. In your case it is half blocked and, depending on the lay of the slab, rainwater may puddle or splash and run through the airbrick and under your house. If you pour a bucket of water on the concrete you will be able to see if the water runs in.

The dark coloured bricks may form the damp course, if they are dark blue clay, not paint. Are you anywhere near Staffordshire? Is this colour of brick common in your area on railway bridges, canals etc?

PigletJohn Fri 07-Aug-20 16:23:56

Also, your picture seems to show some round spots of mortar. Are there quite a number of these, in a horizontal and/or vertical line?

PigletJohn Fri 07-Aug-20 16:25:59


do not contact anyone who sells chemical injections. They will tell you to buy chemical injections.

The only thing you can be sure of is that chemical injections do not cure building faults, or leaking pipes, or broken drains, or high paving.

LachlanConsiden Wed 18-Nov-20 15:08:09

I think you need to think about major repairs of the house. And make high-quality repairs with waterproofing. Now it is very fashionable to have painted concrete, which can be completely waterproof. These stained concrete contractor will help to solve your problem.

LachlanConsiden Wed 18-Nov-20 15:11:26

Message deleted by MNHQ. Here's a link to our Talk Guidelines.

Chumleymouse Wed 18-Nov-20 19:57:43

We had a bit of this in an old house we had, the smell used to come from the soil beneath the suspended ground floors , it was bone dry down there but maybe once or twice a year you would get a musty damp smell. It was probably due to the wind blowing into the air bricks or something like that.

Do you have wooden suspended floors downstairs ?

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