Brick outbuilding --where to start?

[shedvice]

Hi there,

Finally getting around to this after moving house in 2021! We've got a single-skin brick outbuilding, with pretty modern roof and doors/windows. But the brick walls and especially the (concrete) floor are in poor condition, so I'm wondering what to do. It's extremely damp in there -- you can see the mould has appeared on the roof. (It is ventilated I leave the window open.) I'm considering sealing it all up and insulating it, not for a home office exactly because we need the storage, but just to make it a bit more civilised. But I don't want to do that whilst there are major damp issues.

Couple of questions -- do you think that's rising damp on the walls? As you can see the bottom bricks are in far worse shape than those higher up. And you can see that poking up from the edges of the concrete floor in some places is what looks like a plastic sheet... I'm guessing that's for damp-proofing?

I'm a proper beginner here, so give it to me straight!

 

[Mr Chibs]

I thought it was going to be worse

Is there a damp course in the walls? usually two bricks (ish) up from ground level?

Where you think you have rising damp on the photos, what's on the other side of the wall... Is the ground level high? leaking/overflowing gutter etc? Take a couple of pics if you will.

The mold black spots are down to damp conditions and lack of ventilation. Might be able to get those off with bleach & water.

Does the concrete floor not go all the way to the door? i.e. is it just soil here or just need a sweep up?

 

[shedvice]

I thought it was going to be worse

Is there a damp course in the walls? usually two bricks (ish) up from ground level?

Where you think you have rising damp on the photos, what's on the other side of the wall... Is the ground level high? leaking/overflowing gutter etc? Take a couple of pics if you will.

The mold black spots are down to damp conditions and lack of ventilation. Might be able to get those off with bleach & water.

Does the concrete floor not go all the way to the door? i.e. is it just soil here or just need a sweep up?

So sorry for the slow reply! Had to wait for some slightly less awful weather to get decent photos. Not totally sure on the damp course, will have to have a proper look when it's not raining. Thanks very much for your comments.

The outside/external wall is not too bad actually-- the nothing particularly bad. No gutter the building just has a sloping roof. The ground level is a tiny bit higher but nothing major, just a couple of inches. (Photo below) In the past I've noticed the interior of that wall seems particularly wet, almost sweating... but it is opposite the open window so maybe that's it?

I'm hoping to attach the ceiling with bleach and water this weekend, but a bit puzzled -- with the window open and the ceiling 'open' at both ends of the slope, how could there be a lack of ventilation in there? Would this get radically worse if I were to seal it all up with gap fill?

Concrete floor does go to the door -- that was mostly just debrey from me cleaning up a horrible old bookcase that had been left in there! It needs a proper sweep but I've been focusing on getting stuff out of there. I think it's no worse there than in the rest of the edges of the flooring.

Cheers!

 

[Why Not Indeed]

Perhaps the wall doesn't have a DPC at all, looks like signs of moisture on the first 6-7 courses of bricks. Or perhaps there is a DPC but the ground level is higher than it used to be, so the DPC is now too low.

 

[shedvice]

Thanks! Is there any downside to just doing one of those injectable damp proof courses... couldn't hurt, right? There's no plaster or anything so I don't have to worry about that. Medium-term plan is to sort of the damp issue and seal it up so that I can put OSB on the walls or something. (It's not going to be a garden office because my bike and the bbq etc need to live in there... but I wouldn't mind insulating it so I can put a chair in there to relax and read!

 

[Diver Fred]

What is the roof construction? It looks to be a flat roof and some of the joists look to wet in the centre of the spans.

It also looks like damp is coming down the wall rather than up.

Maybe a damp meter wil help clarify which direction it's travelling.

 

[shedvice]

What is the roof construction? It looks to be a flat roof and some of the joists look to wet in the centre of the spans.

It also looks like damp is coming down the wall rather than up.

Maybe a damp meter wil help clarify which direction it's travelling.

The roof is pretty new, couple of years -- the previous one had a giant hole in it so it was replaced when we moved in. It's an angled roof with joists and some kind of fabric on top (I'm not sure of the details sorry). I'm thinking a damp meter might be the thing to do.

 

[Mr Chibs]

Any chance you can take some wider photos showing more of the outside etc, be good to see the whole structure. Can you take photos looking down onto roof?

It looks like a flat roof with slope and presume it's shedding it's water as you have no gutter, this will be adding to the damp wall.

Is this a single skin brick thick? if so, this will be like a magnet for condensation & moisture in damp weather.
You could insulate the inside with PIR on the wall to cut down condensation, this alters the 'dew point' (more reading ) of the wall.

There isn't really any air-flow even though your window is open, you could do with some air vent in the fascia/soffit boards and the insulate the roof.
If you read on here there is a split on how people think this should be achieved, either air gap on top of insulation, or insulation pushed tight to the underside of the roof and forgo the ventilation.

The fabric on your roof, should be roofing membrane, this should be breathable, but obviously it's covered by wood sheets so not as efficient as a roof with roof tiles.

I see blue DPM sheet on the floor (good) but near the back door, it looks like soil, is the floor not complete?

What's that blue disc next to the wall, on the ground?