Soaked walls around window HELP!

JohnoWhits

We bought a cottage (1903) last year and are slowly working our way through the rooms. We have gutted our bedroom and had it re-plastered. The window used to be tiled and would be covered with water in the morning.

We have had brand new windows fitted and the internal exterior walls insulated (we think ultimately we will need the rendering/insulation sorting externally). When our plasterer did the insulation he couldn't do around the window reveals as there was not enough space between the reveals and the new windows.

We currently have soaking window reveals; this isn't just in the morning; it can be any time of day.
I'm assuming there is a thermal bridge here where the reveals are the coldest point. I'm also unsure whether water is seeping through the external wall.

We have checked for gaps outside of the windows and in the attic to check for anything leaking down.

It's currently making a mess of the brand new oak window board and we're worried it's going to ruin the wood. We also can't move on with finishing this room till this is sorted.

We've tried having the windows on the latch; the door open at all times; a de-humidifier but nothing seems to work.

Our plasterer couldn't offer a solution, nor the carpenter.

We just don't know who we need to come and look at this and help us find a solution.

Please help! :huh:

Zola.

seems obvious ...but where there is gaps naturally water is getting in. Until that is sorted you are snookered?

Lorian

I guess this won't be fixed without insulating the reveals. You have no room there at all, for some insulation board?

Do you have a hygrometer (digitial one £5 amazon/ebay). When you get up in the morning what's the relative humidity level in the room at the moment?


Is there a shower room connecting to this room? Does is have good inbound airflow, fan and vent near the shower?

it's also worth having one of these to help spot cold bridging (cheaply). What's the temperature of the reveals, the other walls and the air temp?

https://www.amazon.co.uk/Etekcity-Lasergrip-Non-contact-Thermometer-58%C2%B0F-1022%C2%B0F/dp/B01AT9TON0/

The dehumidifier should help some. what model is it, is it set to make the relative humidity low, say less than 50%, is it place near the window. it needs to be running with the windows and door shut.

As for opening the windows, if you live anywhere near me it wont help so much at the moment - moist mornings outside - the RH here is 85% outside at the moment. last good drying days were the 22nd and 23rd in the afternoons.

Typhoon2000

Well water is either coming from the out side or the inside ( high humidity from newly plastered walls for example). If you had people take look and they cant find any defected with how the new windows were fitted and there aren’t any leaking guterings, then it sounds like high humidity.
You can buy a cheap hygrometer to check.

the_lunatic_is_in_my_head

Is the cottage built from stone? If so are you are using lime plaster?

JohnoWhits

Thanks for the replies. The reveals are pretty snug to the windows to be honest. I'll take a picture and reply when I'm home.


We have got a hygrometer and it always says the humidity is high (way over 60%) unless the sun is out and it seems to dry the walls out and that's the only time it seems to lower. We bought a table top dehumidifier but oddly that's only collecting a small amount of water which is confusing as I thought if it were due to just humidity it would fill up pretty quick.


The wall at the end of our bedroom connects to the bathroom which was re-done at the same time as our room. It's well plasterboarded and the wall there isn't wet at all. We have a fan in there and the door is always shut during showering/bathing and the window always opened after.


Lorain i'm going to look up that link when i'm home and report back once we've got one.


Lunatic yes its stone. I'm not sure what type of plaster was used to be honest- the chap who does our plastering is local and does exterior wall insulation and he seemed pretty clued up and also contacted the manufacturer of the insulation company to check the best way to apply the insulation.

the_lunatic_is_in_my_head

JohnoWhits wrote: »

Lunatic yes its stone. I'm not sure what type of plaster was used to be honest- the chap who does our plastering is local and does exterior wall insulation and he seemed pretty clued up and also contacted the manufacturer of the insulation company to check the best way to apply the insulation.

Ideally stone walls should breathe, natural insulation, natural plasters and natural paint (or as close as these modern breathable paints are).

Our walls are 18 inch thick and although the external walls are insulated from the inside we couldn't insulate the reveals as the windows are small enough as it is.

They (and all the other stone walls) are plastered in lime, the reveals are a cold spot and we get a little bit of black mold from time to time but nothing major.

Modern building materials are cheap and a fair amount of builders aren't sympathetic to stone buildings.

I'd ask the plasterer what plaster has been used on the reveals.

JohnoWhits

So i used my husband's kitchen digital thermometer probe the see if i could get a rough idea of the wall temps. The insulated interior exterior walls are 19; the reveals around 14 and then the gap next to the windows is 12. Obviously a significant difference. There is definitely airflow coming in between the gap between the window board, reveal and underneath. I've heard back from our plasterer and he said that the reveals had previously been skimmed with multi and he also used thistle multi finish would wouldn't be able to tell us what was under the previous work.

Where do we start? Do we just get an insulation specialist in, or a builder?

Fire_Fox

Condensation is generally a lifestyle and whole house/ whole floor issue rather than a single room issue. The plaster drying out and the time of year may have worsened the existing problem.

Your current strategy may simply not be up to the task. Do not underestimate the pints of water we produce daily from breathing, showering/ bathing, air drying laundry indoors, cooking with lids off pans and so on. Reduce these as much as possible.

Throw windows open in several rooms each day and/or use your kitchen and bathroom extractors for much longer and/or get a more powerful dehumidifier for upstairs (several of the Which? Best Buys are Meaco brand).

I also agree with the other that period properties need new materials that work with the original fabric of the building. Modern plasterboard and plaster does not 'move' or 'breathe' like traditional materials. Insulation, if appropriate, needs to be balanced with a solid ventilation strategy. What we think of as draughts (windows/ doors/ chimneys) allowed older buildings to shed excess humidity.

Traditional materials and techniques often make a builing job more difficult and thus quotes more expensive. Generally you will only get that if you educate yourself, then ask the right professionals the right questions. Many builders and many homeowners do not know or do not care about sympathetically restoring period properties.

Mr.Generous

I think the plaster is drawing moisture from the porous stone, the cold will also attract condensation. Chip off the plaster on the returns and do them with plastering sand, ordinary Portland cement and damp proofer additive. Its easier than plastering you should be able to do it yourself if your handy.

the_lunatic_is_in_my_head

JohnoWhits wrote: »

I've heard back from our plasterer and he said that the reveals had previously been skimmed with multi and he also used thistle multi finish would wouldn't be able to tell us what was under the previous work.

Figured that would be the answer.

JohnoWhits wrote: »

The insulated interior exterior walls are 19; the reveals around 14 and then the gap next to the windows is 12. Obviously a significant difference. There is definitely airflow coming in between the gap between the window board, reveal and underneath

How thick are the walls? Ours are constructed of two walls with a load of "rubble" in the middle and you'd never stop all airflow throughout the walls.

You can seal round the windows, board, etc to stop draughts coming into the room but our walls will still be cold due to the airflow inside them.

JohnoWhits wrote: »

Where do we start? Do we just get an insulation specialist in, or a builder?

Have a look on Google for forums dealing with restoring stone properties. Do a bit of research into restoring stone buildings so going forward you can use better materials.

Internal wall insulation for exterior walls should be natural, but it's pointless using them if the wall is then plasterboarded and skimmed with multi-finish.

We used wool boards and lime hemp plaster instead of PB and multi, you can get a finishing lime plaster for a smooth finish.

The suggestion above is an example of what not to do, you'll just seal the moisture inside the walls and possibly end up with dry rot.

Take multi finish as an example, someone patched several bits of plaster in our house with this stuff directly on to the stone wall and over time it traps moisture, the paint starts to peel and then the plaster crumbles (don't panic, our house sat pretty much empty for 50 years and was extremely damp) but as above there are cold spots in the walls and lime breathes meaning the moisture can be released.

If your cottage is a row of terraced houses keeping each other warm and relatively sheltered from the weather keeping the house heated and free from damp is going to be much easier than a detached cottage surrounded by open fields.

Using natural materials is expensive, if this is your forever home it's worthwhile IMHO, if it's not and you plan to move in say 5 years try to find a balance but for your specific concern of the reveals going forward I'd knock them back to stone and plaster with lime.

All that said you may find once the water from the plaster drying is gone the damp on the reveals isn't so much of an issue.