Damp and dehumidifiers

[Rudi McAnichal]

Damp inside, dry outside might indicate leakage into the cavity. Would there be bathroom, toilet, or any water pipes above the damp area? Any holes drilled or nails knocked into the walls recently that might have damaged a pipe?

A domestic type dehumidifier can be very useful when you feel a slight dampness in the air (long session with washing machine, several people taking showers one after the other, etc), but those photos make me think it would be better to hire in a big industrial dehumidifier while you get the problem sorted.

We have two of the desiccant type dehumidifiers, one Meaco, the other Eco-Air, no problems with either of them. Previously we used an Ebac (refrigeration type) that worked very well until it died at around 10 years old. General advice seemed to favour refrigeration type for warm climates and desiccant if you live in a cold locality. We just use the built-in tanks and empty them every few days, but a continuous drain would be better for your rather serious dampness problem.

SWMBO inherited a little old cottage (listed building) with visible dampness, solid sandstone walls, nasty modern cement rendering, no proper damp course, and a sitting tenant who was increasing the moisture content by using a Calor gas heater. She gave the tenant a couple of fairly cheap dehumidifiers, which were an enormous improvement. It was 300 miles from where we live, so she was pleased to find a buyer for the place and get shot of the problem, but might have thought differently if she had known how folk would be fighting one another to pay a fortune for almost anything this summer.

 

[gaz1]

Doorways not damp, but we did do the floor last year, leveled with tiles, so Id be very worried if the front doorway/hall was damp!

Gutters, you share my sceptism. Last time they were here I saw they had splashed water around but appeared to leave the windows wet and somewhat dirty.

Theres no cavity insulation. Im tempted to drill a small hole from inside, for my bore camera and have a look in the cavity but might show nothing.. the moisture meter readings are higher inside than out, so suggests its not getting in, or outside has dried off since - gets the sun.

Not aware of any earthquake. The mains water does run under the problem area, and I would say the garden is unusually moist for this time of year, but we do not suspect a mains leak.

last earthquake we had would have broken any water seal to the outside on any walls the only material to stand that damage would have been lime mixture that would self seal

your pics say differently they say your silicone seal has broken as its more at the frame than from the internal corner going in



and a better look at your cavity is break down by the side of the door less damage there and easier to repair

mains water leak can show what your seeing

 

[Kram]

your pics say differently they say your silicone seal has broken as its more at the frame than from the internal corner going in

Had a look outside and your right, the outside seal has gaps. Im going to rake the seal and redo it. What is recommended?

 

[Red'n'Black]

Another +1 for Ebac, bought one to replace a no-name ebay desiccant type. Mainly used for drying clothes in the bathroom in winter, but it helps keep the room dry in general.

I saw Ebac also do a made-in-UK washing machine, which was a pleasant surprise. Not cheap but tempted to give it a go when our Bosch eventually dies.

 

[JMS1972]

Had a look outside and your right, the outside seal has gaps. Im going to rake the seal and redo it. What is recommended?

Exterior silicone and cover it with plastic quadrant or other shaped trim if possible. The trim protects the silicone from the worst of the weather so it lasts longer. Trim will stick to the silicone....

 

[Kram]

This is the outside.

The sealant came out easily. I suspected the bottom as the sealant ends at the sill, no foam or sealant. My screwdriver goes straight through to the skirting
Back inside, pull the skirting off for a look behind, and vacume all the dust. We have a big hole!

There appears to be 3 sheets of black DPC, one coming down?! and a clear piece of something. The cement appears either washed away or crumbled, not good! How should I fix this?

Behind the sealant was foam. I decided the gap was too big, so a can of foam was applied from outside. I got some Unibond exterior sealant but forgot quadrant so I'll get that and finish outside tomorrow.
There is some pointing to do as well.

Correct PPE was used, @Parm a relatively new and clean jumper, ruined! One on the left is my dirty old jumper I thought I was wearing

New foam with a sensible gap for sealant.

 

[123hotchef]

Not aware of any earthquake. The mains water does run under the problem area, and I would say the garden is unusually moist for this time of year, but we do not suspect a mains leak.

what is the mains piped in?

 

[Kram]

I dont know, what was cheapest for 1960-1970 builds?

 

[S-Rail]

I’ve got to ask , has your place either …

1) got any cavity insulation at all
Or
2) been retrofitted with cavity insulation be it polystyrene balls or injected expanding foam type

as they seems a bit more than just average condensation

and as a side note , I would clean that wall down with bleach or similar and be careful breathing that in as the spores can make you quiet poorly

 

[123hotchef]

I dont know, what was cheapest for 1960-1970 builds?

hum copper or iron i bet it aint 100% water tight anymore, are you on a water meter?

 

[Kram]

Nope never been done here, but is that a vertical peice of DPC, supposed to be there, inside the cavity?

There was a leak 3 houses down last year, just after they had a meter put in.

 

[123hotchef]

hard to tell from that pic regarding the DPM.

my money is on a water leak under ground

 

[gaz1]

the dpc up piece wont go far only a seperator between outside wall and inside wall i bet

the one on the inside is dpc and the one on the window is the new dpc

of coarse filled with foam and not much else will be surprised if theyve screwed the frame in

scrape the foam outside until its below level of the frame then its cut the slicone end to size bad habbit i can do mine really well

do a fast layer but dont smooth it you need another layer over it this will build a good thicknes to seal and smooth out to the frame and wall

but must be cleaned on both well