Damp patch has us stumped

ChasingtheWelshdream

Thank you all.

Freebear: That’s good to hear, we really have been clutching at straws as you can tell! The reason I wondered about degrading is because where I have repointed outside and replaced some bricks, I couldn’t avoid some of the dpc coming away. As it was crumbling in my fingers I just assumed it maybe wore away over time.

Coffeehound, CoffeeKup and Stuart:
I hadn’t thought of condensation! But that makes sense, although I am confused why it is so localised and haven’t ever experienced it at floor level so didn’t even consider it. I will definitely go down that route for investigation. Which actually makes me happy as I can deal with that.

 I am looking to get some hygrometers anyway as mould has appeared on the dining room ceiling for the first time and we need to tackle the causes. We run a dehumidifier over winter because of the washing (which will eventually move to the utility room in future laundry room plans), but we don’t actually know the humidity levels. 

We have linked this to the opening up of the rooms and the kitchen moisture now percolating through. We didn’t really use the back room much before and now it is open to cooking, living and washing.

As well as an uninsulated floor, old windows without trickle vents, no insulation above the bay window and no extractor in the kitchen. We have a fair bit to do! Sadly we can’t stretch to digging and insulating the kitchen floor yet but will be doing the timber floor.
 

Looks like it may all be linked. 

coffeehound

ChasingtheWelshdream said:

I hadn’t thought of condensation! But that makes sense, although I am confused why it is so localised and haven’t ever experienced it at floor level so didn’t even consider it. I will definitely go down that route for investigation. 

The very blustery weather over the past few weeks could be contributing too.  The constantly changing wind direction could cause the airflow to 'push and pull' through the gap so that you have ice-cold air coming in, alternating with warm humid air being sucked out, so a sort of perfect storm for condensation at the entry point

FreeBear

ChasingtheWelshdream said:  I am looking to get some hygrometers anyway as mould has appeared on the dining room ceiling for the first time and we need to tackle the causes. We run a dehumidifier over winter because of the washing (which will eventually move to the utility room in future laundry room plans), but we don’t actually know the humidity levels.

Somebody over on another forum (Period Property Forum) posted a link to a hygrometer that they have purchased. Has the ability to store the readings (apparently) and let you view them via an "app" - https://www.amazon.co.uk/dp/B086YYL439/?th=1

If you are tech savvy, and have a spare computer lying around (a Raspberry Pi for example), then I can recommend Home Assistant with some cheap humidity/temperature sensors attached. I have HA set up here along with humidity/temperature sensors around the house. Whilst the data is of passing interest, the real value is looking at the graphs as various "improvements" are made. Having insulated the walls of one bedroom, I can see straight away that it is much quicker to heat up with a very small radiator. Can also see how much difference it makes to humidity levels if I dry washing inside - Surprisingly, very little.

ChasingtheWelshdream

Ooh, sounds very technical but I will definitely have a look. We have plenty of IT around but haven’t yet gone down the smart home route so it might be time to start.

Thanks!

ChasingtheWelshdream

Just thought I'd update this (as I always like to see endings myself).

I haven't managed to get around to doing anything technical with hygrometers yet. We went away for a week over Christmas. The heating was was off (frost protection excepted), so the house was cold but also no moisture generated from general living. Even with the dehumidifier off for the week we returned to a dry wall, despite the seemingly never-ending wet Welsh weather whilst we were away.

So we must conclude it is indeed a strangely isolated cold spot of condensation exacerbated by cooking/washing/living. Which although not great, is not so panic-inducing as other kinds of damp. 

Rosa_Damascena

ChasingtheWelshdream said:

Just thought I'd update this (as I always like to see endings myself).

I haven't managed to get around to doing anything technical with hygrometers yet. We went away for a week over Christmas. The heating was was off (frost protection excepted), so the house was cold but also no moisture generated from general living. Even with the dehumidifier off for the week we returned to a dry wall, despite the seemingly never-ending wet Welsh weather whilst we were away.

So we must conclude it is indeed a strangely isolated cold spot of condensation exacerbated by cooking/washing/living. Which although not great, is not so panic-inducing as other kinds of damp. 

I'm interested to hear what the proposed fix is. Or are you going to leave it?

ChasingtheWelshdream

Rosa_Damascena said:

I'm interested to hear what the proposed fix is. Or are you going to leave it?

As well as making good - boarding over the brickwork and sealing the gaps to the under floor void - we will also be insulating under the floor boards (and draughtproofing), and adding ventilation (vent on chimney breast, kitchen extractor, replacing windows and adding appropriate trickle vents). I will also be adding a radiator as the only heat in the kitchen is from a range. There is only one exterior wall which is under the bay window (also now showing signs of condensation) so we will insulate this when we replace the windows. If we can, we will try to fit some insulation into the bay window roof, but it may be too tight. We'll see.

That, and finally getting round to sorting the utility room into a proper laundry room, so stopping drying clothes above the range, will hopefully go a long way to sort. 

The one thing I would love to do, but can no way afford, is to excavate the kitchen floor and put limecrete/insulation down. Unfortunately, way, way too expensive for the foreseeable, so we will be using rugs for a good while. 

Rosa_Damascena

ChasingtheWelshdream said:

Rosa_Damascena said:

I'm interested to hear what the proposed fix is. Or are you going to leave it?

As well as making good - boarding over the brickwork and sealing the gaps to the under floor void - we will also be insulating under the floor boards (and draughtproofing), and adding ventilation (vent on chimney breast, kitchen extractor, replacing windows and adding appropriate trickle vents). I will also be adding a radiator as the only heat in the kitchen is from a range. There is only one exterior wall which is under the bay window (also now showing signs of condensation) so we will insulate this when we replace the windows. If we can, we will try to fit some insulation into the bay window roof, but it may be too tight. We'll see.

That, and finally getting round to sorting the utility room into a proper laundry room, so stopping drying clothes above the range, will hopefully go a long way to sort. 

The one thing I would love to do, but can no way afford, is to excavate the kitchen floor and put limecrete/insulation down. Unfortunately, way, way too expensive for the foreseeable, so we will be using rugs for a good while. 

I ended up doing just that - an unforeseeable additional expense to the build but I didn't see the point of putting expensive brand new flooring down to cover up the problem. It was expensive but I don't plan to worry about it again, just working like a dog to get it all paid off now!

ChasingtheWelshdream

Oh if we could I would. But going to have to save for a very long time and other projects are more pressing. We won’t be putting a floor down until we can do it though. I’ve hated the floor for years, will just have to hate it for a few more!

Rosa_Damascena

^^^^ The room is 16'x12'6". You can see why fixing it was pricey!