Damp, with a sprinkling of mould

[Polaralias]

Hello DIYnotters!

Got a few questions regarding damp but some useful info beforehand:
Property is end terraced, built around 1990, in Swansea, no subsidence/coal mining nearby and lastly - the house has ventilation grills that cover holes drilled through to the exterior of the building in nearly every room.

Q1: Why would there be damp in the ceiling and walls of the first floor bedroom at the rear of the property? The walls sometimes feel moist and mould will crop up often after a rainy spell. The paint on the ceiling is peeling and feels wetter than the walls but no obvious drips. Current theory is damaged tiling/roofing underlay.

Q2: Why would there be damp/peeling paint on the ceiling and rust on the angle beading in the kitchen (below the room above). Again no obvious places water is coming in and afaik the pipes aren't damaged. Current thinking here is this is coming down from above but the rust is on every piece of angle beading at random spots.

Q3: Why would the connecting wall between the kitchen and living room be damp? Removed the doorway and it was wet on the wall-side with damp behind but no obvious damage to the external render or obvious water ingress points. There isn't any damp in the floor above in the same spot. No real thoughts here.

Q4: Why would there be so many ventilation spots (grills covering holes drilled all the way through the wall) and is this how they should the actually be installed?

Q5: Should we be worried about cracks about 1mm wide on the front wall on the ground floor and either side of a supporting beam on the first floor?

Q6: Why are independent damp surveys so expensive?!


I'm aware this is a very vague post but if anyone has any pointers on the above it would be very appreciated, just a list of all the possible causes of damp would be great if anyone has one

 

[Swwils]

Most possible it's real leaks and water ingress.

Causes can be wide and varied.

Real damp expertise is rare and it's very involved, hence the cost.

Post some photos of the problem areas and I'm sure others can offer assistance.

 

[^woody^]

How have you determined that these materials are damp?

There is dampness caused by the structure, and dampness caused by the people living in the house, and yours sounds like the latter.

Parts of a building facing certain directions are more prone to exhibit condensation dampness as mould.

Numerous vent holes in walls may be some sort of discredited damp prevention system or radon ventilation.

1mm cracks are nothing to worry about.

Whether the cost of damp surveys is expensive is relative. £5 for mini fish and chips is expensive.

 

[JohnD]

Damp ceilings suggest condensation. If a previous owner has added extra wall vents it may be a long-standing problem.

If it is a particular bedroom it might be lack of ventilation combined with persistent breathing. Or steam from a nearby bathroom that is not extracted away.

Are the ventilation holes open or blocked?

How is the kitchen ventilated? Water vapour is lighter than air and will rise through the house, especially if there are holes in the ceiling, for example downlighters.

One common cause is often wet washing draped on radiators and airers.

Another can be excessive humidity caused by a leak that is not visible, for example under the floor. Or sometimes a high water table, again causing subfloor damp, though with wooden floors, this can be reduced by generous ventilation of the subfloor void by the airbricks.

Have you got a water meter?

 

[JP_]

Did you mean 1890? Or were they really still making homes with vent grills in 1990?

 

[Polaralias]

Did you mean 1890? Or were they really still making homes with vent grills in 1990?

That's according to land registry but I was a bit sceptical tbh, the vent grills do look a bit shabby so wonder if they were installed later...

 

[Polaralias]

Damp ceilings suggest condensation. If a previous owner has added extra wall vents it may be a long-standing problem.

If it is a particular bedroom it might be lack of ventilation combined with persistent breathing. Or steam from a nearby bathroom that is not extracted away.

Are the ventilation holes open or blocked?

How is the kitchen ventilated? Water vapour is lighter than air and will rise through the house, especially if there are holes in the ceiling, for example downlighters.

One common cause is often wet washing draped on radiators and airers.

Another can be excessive humidity caused by a leak that is not visible, for example under the floor. Or sometimes a high water table, again causing subfloor damp, though with wooden floors, this can be reduced by generous ventilation of the subfloor void by the airbricks.

Have you got a water meter?

Had one installed about a month ago as there wasn't one originally so yes to the water meter. Afaik the floors aren't suspended downstairs but I'm not sure what's under the laminate planks upstairs.

The ventilation holes are open but not all of them all the way, should they be?

The bathroom is adjacent to the bedroom with issues though the bathroom walls are covered in the plastic sheeting stuff, could water come through the ceiling?

We have a tumble dryer so very rarely pop clothes on the radiators.

The kitchen hasn't got any ventilation now I think about it, there is an extractor fan that doesn't seem to have an exhaust of any kind!

 

[Polaralias]

How have you determined that these materials are damp?

There is dampness caused by the structure, and dampness caused by the people living in the house, and yours sounds like the latter.

Parts of a building facing certain directions are more prone to exhibit condensation dampness as mould.

Numerous vent holes in walls may be some sort of discredited damp prevention system or radon ventilation.

1mm cracks are nothing to worry about.

Whether the cost of damp surveys is expensive is relative. £5 for mini fish and chips is expensive.

Afaik radon came back ok on the builders survey when we bought the place so reckon the vents are for damp.

I've noticed bubbling in the shein paint both in the kitchen and bedroom that I can then pull off although no water drips down. The wall in the bedroom has felt damp/wet on a few occasions and the mould is visible at times. The angle beading is a bit more obvious as the rust sticks out like a sore thumb! The other spots had the salt dust stuff that comes up when plaster is moist (I think?!) and you could see mould there on occasion too

 

[JohnD]

...The bathroom is adjacent to the bedroom with issues ...

...The kitchen hasn't got any ventilation now I think about it, there is an extractor fan that doesn't seem to have an exhaust of any kind!

Do you mean that neither the kitchen nor the bathroom have functioning extractor fans?

 

[Polaralias]

Do you mean that neither the kitchen nor the bathroom have functioning extractor fans?

Bathroom definitely not, kitchen has this https://www.howdens.com/kitchens/ap...0cm-stainless-steel-visor-cooker-hood-lam2105 which just seems to recirculate?

 

[JohnD]

fix both those rooms then. They will be fill of steam and you need to get it out of the house. If you are burly, you can get a huge drill and 110mm or 125mm core cutter from a tool hire shop. It is very heavy. A plumber or builder can also do it. If you do not already have a ventilator in the damp bedroom, consider coring a hole there as well, near the ceiling, at the same time. if necessary, you can add a vent or fan later.

There are also some cheap ones to buy that will do the job.

the bathroom fan can conveniently be wired to the room light. You will probably need an electrician. If you have access to the loft you can get a ducted fan that is preferable, because quieter and more powerful. Some people turn fans off if they havew one that is annoyingy noisy.

Would it be rude to ask if cost is a problem?

 

[Polaralias]

fix both those rooms then. They will be fill of steam and you need to get it out of the house. If you are burly, you can get a huge drill and 110mm or 125mm core cutter from a tool hire shop. It is very heavy. A plumber or builder can also do it. If you do not already have a ventilator in the damp bedroom, consider coring a hole there as well, near the ceiling, at the same time. if necessary, you can add a vent or fan later.

There are also some cheap ones to buy that will do the job.

the bathroom fan can conveniently be wired to the room light. You will probably need an electrician. If you have access to the loft you can get a ducted fan that is preferable, because quieter and more powerful. Some people turn fans off if they havew one that is annoyingy noisy.

Would it be rude to ask if cost is a problem?

Thats really helpful thanks not rude no! Wouldn't say cost is a problem, more that I'm frugal and want to do it as cheap as possible (sounds bad now I write it down)

 

[JohnD]

if you are not used to this sort of work, ask around for recommendations, from people you know and trust, of a local electrician. Don't use advertising websites where the traders pay to be listed, even if it masquerades as a recommendations website of trusted or rated advertisers.

I see your hood needs a 125mm duct. Have it pretty high, because the spigots on modern hoods usually comes out of the top, and you will need an elbow as well. If you buy a different hood in future, it might be bigger and you don't want it to be low enough to bang your head on. Some are about 350mm tall.

 

[Polaralias]

if you are not used to this sort of work, ask around for recommendations, from people you know and trust, of a local electrician. Don't use advertising websites where the traders pay to be listed, even if it masquerades as a recommendations website of trusted or rated advertisers.

I see your hood needs a 125mm duct. Have it pretty high, because the spigots on modern hoods usually comes out of the top, and you will need an elbow as well. If you buy a different hood in future, it might be bigger and you don't want it to be low enough to bang your head on. Some are about 350mm tall.

Quite capable with the majority of DIY stuff, converted 2 vans into campers so willing to give most things a go

So you reckon we need to run the extractor outside in the kitchen as oppose to just recirculating?

 

[JohnD]

definitely

a recirculating hood is nothing but an expensive ornament.