Hello all, quite a long post but I thought I'd include all information I have at this point so you can best advise me.
I'm in a bit of a pickle with my house and any advice would be greatly appreciated. I have a small mid-terrace Victorian house with suspended wooden floors. I rented it out for the first year of owning it, since moving in a few weeks ago I noticed a really damp smell and that the humidity was high - in most rooms it's about 70% with the windows ajar - opening them fully lowers it to about 66%, which is still way too high for the fabric of the house and for my health.
Fast forward and I've removed the carpet and damp underlay and seen the floorboards are damp. I removed some boards and looked into the crawl space to see standing water a couple of inches deep in two areas, totalling about a third of the room. Obviously this water is evaporating up into the room through the floorboards. Other things I noticed were that the joists were more or less dry, as well as the underside of the floorboards (this seemed strange but would suggest the air bricks are doing their job).
First thing I did was fully clear the partially blocked air bricks. I then scooped out half a bucket of water from one of the areas until it was very shallow, after this I put the heating on and all the taps, flushed the loo etc. and observed, nothing happened. Being Manchester it wasn't long before it rained - pretty heavily, and when I looked through the hole a few hours later I saw the ground now had LOTS more water on it. The relative humidity in this room is now about 75% with the window ajar (there is no longer carpet and underlay on the floorboards).
So cause-wise I'm thinking it's either a faulty drain, or rainwater - either due to the water table or seepage from somewhere? I am speaking to my insurance and will look into getting the water tested and drains checked.
Best case scenario is it's a faulty drain which can be fixed, and the problem goes away. More likely, the drain survey will show all is fine and I need to combat the natural water, for which I will have a few options, and really this is where I need advice:
1. concrete (probably self-levelling) the crawl space. Am I right in thinking the water will not get through the concrete? Where will it go, will it just move around underneath the concrete looking for its way out (probably the neighbours?). I believe this is expensive... does anyone know approx cost per m2?
2. install a sump pump. While this will drain water away, I can't imagine it gets rid of all the water - and while this is the case I am worried the problem of it evaporating into the house won't go away. Also I might need another sump pump for the living room to the rear of the house which I haven't looked under yet (or will one suffice for the whole floor?). These don't look too difficult to install myself, though I expect I would need a plumber for checking it over/helping divert the pipe to the rear yard drain.
3. put a DPM sheet down. This would stop most of the water evaporating straight up, I think, but the question is would it just go to the edges and come up there? One idea is if I laid gravel down on the DPM around the edges of the room, but did not 'seal' it down at the front of the house where the air three bricks are, the moisture would find its way to this point and rise up and (possibly?) vent out of the air bricks - much like a bathroom window. Is this likely at all? The incoming air from the air bricks would still circulate above the DPM and do its job of convecting moisture off the woodwork.
I will update when I have more information about the water table, after I've had any drain inspections done and generally have more of an idea of the root cause of this. I have drawn a little diagram looking from the hallway side of the room so the issue is clear. Also there is one picture of the lovely, 'inviting' crawlspace showing a bit of water (what I originally saw before it'd rained). Note, there is more water to the right of that in the picture.
Your experience, expertise and any advice on my 3 potential solutions would be very warmly appreciated.
I'm in a bit of a pickle with my house and any advice would be greatly appreciated. I have a small mid-terrace Victorian house with suspended wooden floors. I rented it out for the first year of owning it, since moving in a few weeks ago I noticed a really damp smell and that the humidity was high - in most rooms it's about 70% with the windows ajar - opening them fully lowers it to about 66%, which is still way too high for the fabric of the house and for my health.
Fast forward and I've removed the carpet and damp underlay and seen the floorboards are damp. I removed some boards and looked into the crawl space to see standing water a couple of inches deep in two areas, totalling about a third of the room. Obviously this water is evaporating up into the room through the floorboards. Other things I noticed were that the joists were more or less dry, as well as the underside of the floorboards (this seemed strange but would suggest the air bricks are doing their job).
First thing I did was fully clear the partially blocked air bricks. I then scooped out half a bucket of water from one of the areas until it was very shallow, after this I put the heating on and all the taps, flushed the loo etc. and observed, nothing happened. Being Manchester it wasn't long before it rained - pretty heavily, and when I looked through the hole a few hours later I saw the ground now had LOTS more water on it. The relative humidity in this room is now about 75% with the window ajar (there is no longer carpet and underlay on the floorboards).
So cause-wise I'm thinking it's either a faulty drain, or rainwater - either due to the water table or seepage from somewhere? I am speaking to my insurance and will look into getting the water tested and drains checked.
Best case scenario is it's a faulty drain which can be fixed, and the problem goes away. More likely, the drain survey will show all is fine and I need to combat the natural water, for which I will have a few options, and really this is where I need advice:
1. concrete (probably self-levelling) the crawl space. Am I right in thinking the water will not get through the concrete? Where will it go, will it just move around underneath the concrete looking for its way out (probably the neighbours?). I believe this is expensive... does anyone know approx cost per m2?
2. install a sump pump. While this will drain water away, I can't imagine it gets rid of all the water - and while this is the case I am worried the problem of it evaporating into the house won't go away. Also I might need another sump pump for the living room to the rear of the house which I haven't looked under yet (or will one suffice for the whole floor?). These don't look too difficult to install myself, though I expect I would need a plumber for checking it over/helping divert the pipe to the rear yard drain.
3. put a DPM sheet down. This would stop most of the water evaporating straight up, I think, but the question is would it just go to the edges and come up there? One idea is if I laid gravel down on the DPM around the edges of the room, but did not 'seal' it down at the front of the house where the air three bricks are, the moisture would find its way to this point and rise up and (possibly?) vent out of the air bricks - much like a bathroom window. Is this likely at all? The incoming air from the air bricks would still circulate above the DPM and do its job of convecting moisture off the woodwork.
I will update when I have more information about the water table, after I've had any drain inspections done and generally have more of an idea of the root cause of this. I have drawn a little diagram looking from the hallway side of the room so the issue is clear. Also there is one picture of the lovely, 'inviting' crawlspace showing a bit of water (what I originally saw before it'd rained). Note, there is more water to the right of that in the picture.
Your experience, expertise and any advice on my 3 potential solutions would be very warmly appreciated.
