Two walls of my house are now suffering from damp issues (visible on paintwork inside). One is in the living room and has nothing in front of it to trap moisture and cause this problem. The other is perhaps a little more expected as it's a built in wardrobe with an external wall. However, two air vents have been situated in the wall to allow air flow.
Either way, as I said I'm having damp problems with both. I'm sure I could solve this by painting PVU glue on the walls but Ideally I'd like to know why it's happening. Any help out there??
How old is the house? Has double glazing been fitted after it was built? How is it heated and to what temperature? How is it ventilated? How do you dry washing? (If tumble dryer is it vented outside or condenser type?) Number of floors? Number of occupants?
Did you mean PVA glue? If so, it won't be effective at blocking damp.
SBR would be more effective, but you'll have to dilute it and apply many coats until the wall won't accept anymore. Even SBR used in this way isn't
100% effective - it is more when it's used as an additive to render or screed.
However, that said, there are some other considerations;
a) If you prevent the moisture from escaping, it's going to traverse the wall more, eg upwards and you'll possibly just move the problem.
b) Where's the damp coming from? Do you suspect you don't have an effective DPC course, or is there another soluable problem such as earth outside bridging the DPC (remove earth), or rainwater flooding on the path and overflowing above the DPC (dig trench, fill with gravel aka French Drain).
It would be better to solve the ingress of damp before trying to thwart its egress. The latter is usually harder or moves the problem around.
There's no such thing as "PVU" glue. If you mean PVA glue then it does absolutely nothing to protect a wall against damp.
Asking someone to come up with a permanent solution to damp without giving any details is umm, not really going to get you far.
Knowing the age of the property and the construction of the wall would help. For example my own home is old and does not have cavity walls. It has massive brick walls (five to eight courses of bricks on external walls) no DPC no foundations to speak of and the walls sit on the chalk bedrock. Damp is therefore a potential problem but we have none because outside we have laid a French drain around the house and inside we take care to only use finishes and building materials that permit transpiration of water. The walls and the atmosphere are in balance and damp does not penetrate.
We also keep the leadwork and gutters in good condition which prevents water penetrating from above or through the walls.
If you have a house with cavity walls then your problems could be either a breached DPC or water penetrating from faulty guttering or blocked downspouts. You need to check the outside of the house first before you start piddling about and painting things on the walls.
Get out there with your umbrella next time it rains and see whether any part of the wall(s) is getting more than its fair share of water. What surface have you got outside? Brickwork, render?
How old is the house? 1950's bungalow Has double glazing been fitted after it was built? double glazing about 15 yrs. old at a guess - lots of moisture collects on living room and bedroom window (living room wall next to the window is where one of the damp problems is) How is it heated and to what temperature? combi boiler - kept at around 15 degrees during the day - 20 degrees in the evening - overnight will fall to around 12 degrees How is it ventilated? not entirely sure - only bought the place 6 months ago - no sign of any air bricks if that's what you mean How do you dry washing? (If tumble dryer is it vented outside or condenser type?) no tumble dryer - washing is dried using heated towel rails in two bathrooms Number of floors? 1 Number of occupants? 4
...and yes I did mean PVA glue - sorry. The built in wardrobe as I said has two vents to the outside, but still suffers damp problems. The gutters were cleared out this summer and a brief inspection of the outside of the building shows the gutters are still clear - there is some slight buckling on some of the 'barge' boards? The horizontal wooden sections which overhang the walls and meet the gutters.
The problem is simple to diagnose; you have insufficient ventilation and you are at risk of chronic condensation which will eventually lead to black mould and possibly worse.
The answer is to start opening your windows regularly. See if any air bricks have been blocked up and, if so, unblock them.
You should also review your method of drying clothes, because the method you use now will inevitably release large amounts of moisture into the air inside the house.
In the longer term you should consider installing cavity wall insulation which will raise the temperature of the interior surface of your external walls and therefore reduce condensation.
However, nothing should deter you from increasing the amount of ventilation. Open those windows!
Not simple at all. The OP might like to see whether the problem persists when the weather is cold but not wet, thereby discounting penetrating damp. IME condensation is unlikely if the temperature is maintained at the levels he has quoted.
I note you carefully deleted my comments about drying washing on radiators. This is quite clearly someone whose family generate an awful lot of moisture within the building but don't open windows.
The washing generated by four people will be approx 1 full load every day? - this amount of clothing will hold about 4 pints of water per load and it has to go somewhere.....21 pints per week = a lot of moisture. It's condensing on the coldest parts of the walls, either get a vented tumble dryer or a condensing one, failing that, get a dehumidifier in the room where you are drying clothes, or close the door and leave the window open.
Are the outside walls wet where this damp is showing inside? - part of it may be penetrating or rising damp, and there's nothing you can paint on to cure this, but on a 50's house, it's unlikely, but not impossible that the dpc has failed
That is pointing towards condensation rather than damp being the cause.
In a bungalow with no cavity wall insulation that is sufficiently low to cause condensation to form on some walls.
I presume the windows frames have no ventilators at the top?
That is pointing towards condensation rather than damp being the cause.
I would be very surprised if you have a damp (as in damp coming from the outside) problem. It seems almost certain you have a condensation problem with very moist air inside the house condensing on the cooler walls and windows. It is very common on bungalows of that vintage where double glazing with no, or inadequate, ventilation was fitted later.
The only cure is to reduce the humidity in the house. You can minimise the condensation on the walls by having cavity wall insulation fitted (and save on heating bills) but you really need better ventilation.
A stop-gap is to use a de-humidifier. This will reduce the moisture content of the air sufficiently to minimise the problem and will help with getting rid of the extra moisture caused by drying clothes inside.
Painting glue on the walls will have absolutely no effect. For the wardrobe, lining the wall at the back of the wardrobe with polystyrene tiles will help. Two ventilators are insufficient by themselves.
Ultimately, however, the only real cure is to sort out the ventilation.
On a related note, the vents in the wardrobe would work better if there is a vent fitted either into the door or the side of the wardobe, to allow airflow - as it is, air isn't going to circulate properly if the wardrobe is sealed
Thanks for all of the comments and advice. Bruce...I didn't deliberately ignore your comments on drying washing on radiators - I'm well aware that this will of course increase moisture content in the air but without a tumble dryer have little option. Phil L...we do around 2 - 3 full loads of washing per week so probably generate around 1/2 the amount of water into the atmosphere that you calculate.
My solution would appear simple then...
Open some windows!
Buy a tumble dryer (will probably be more use in the long run than a dehumidifier) to prevent additional moisture from drying clothes
Keep the interior temperature higher to avoid condensation forming in the first place
Possibly install cavity wall insulation if the above have no effect
CWI can be had for free or very cheap these days - often cheaper than loft insulation and it will make the house more comfortable and save you quite a bit of money too, if it were me it would be my first port of call - I dry all my washing on the rads from Sept - May and don't get any condensation anwhere, this is because I have an open fireplace (ventilation) and CWI. Th interior temperature is more stable because the heat is trapped in and the walls stay warmer, so just by having CWI, you could save yourself the cost of a tumble dryer, the cost of extra fuel to heat the place and a warmer home.
Airing the house every day has much to commend it.
That will certainly help a lot - if the dryer can go on an outside wall get a vented dryer and make a hole in the wall to take the vent pipe rather than a condensing dryer - the latter tend to release moist air into the room. Vented dryers are also cheaper and more reliable than condenser types.
Yes
I'd go for this anyway. It has a short payback period, can make the house much more comfortable and there seem to be quite a few grants etc you can get to have it installed.
While you are at it look at the insulation in the roof space as well. The better insulated the house is the cheaper it is to keep it at a temperature high enough to minimise condensation.
I'd sooner shovel the 2kW or so into the house rather than heat the garden.
Whilst I agree there may be some leakage of moist air out of a condensing drier, it's minimal in my experience. In anycase, a vented one has similar leaks as the tumbler volume works in positive pressure.
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