Mysterious dampness to picture rail and architrave??

[zenonithus]

Hello all,

The other day I drilled holes and nailed in the old picture rail just under the ceiling. All seemed fine until I got home a day later and noticed a damp wood smell. I can see some of the wood is a little damp in areas. I noticed some of the rail over the living room door the other day had a slight bit of dampness, that seems to be dry now. Now I have noticed the rail above the kitchen door is slightly dam and there is dampness on the left architrave mainly in the middle.

I should have used a pipe detector before nailing in the picture rail though I really don't think there are water pipes in the walls as all my water runs under the floorboards. There are visible water pipes from the loft in the bathroom cupboard. I have seen old black metal paipes in the walls though I'm pretty sure these are decommissioned electrical pipes. The walls seem to be dry. you can see the fairly damp areas where the wood is darker.

Can anyone shed any light on this issue?

 

[zenonithus]

You can see with the picture rail the damp ends at the end and the rail it is butted against is dry. Also I do sometimes leave my bathroom door open after a shower without opening the window so not sure if this has anything to do with it. There are small areas of the skirting board opposite that are slightly damp. I am on a 1st floor flat. Also it was raining heavily the other night so could it be down to a leak in the roof? Is the water travelling through the nails and if so why are only some areas of the architrave (middle) affected?

 

[big-all]

i would suspect a pipe
do not remove the nail gradually dig around the area about 5mm deep at a time until you resolve the issue
worth locating your stop cock

do you have a pressurized heating system ??

 

[zenonithus]

hey big-all, thanks for the reply. It would be hard to remove the picture rail without removing the nail as when pulling it out the nail comes with it. From what I can see the water main is coming from the kitchen and there is a visible water pipe coming from the ceiling at the other end. All the central heating copper pipes are underneath the floor. I guess another thing to clarify would be to try and take off the floorboard to see if there is a pipe running at the bottom of the wall. Though What I cant explain are why some parts of the wood are dry and some have this tacky slight damp feel? And I have been noticing patches on wood in other areas. The picture rail on the other side far back had this dampness but now seems to have dried up.

 

[HERTS P&D]

I've been to a call out where a customer went through the lead rising main when nailing a picture to the wall.

Andy

 

[zenonithus]

Oh really? yeah I think I may have to take it all off and start chipping into the wall. Is it possible it is just the one pipe in this area? Or would there be more on the other walls? Would a pipe/wire detector pick up the pipe or do they not detect lead or iron pipes and only copper?

What would be the best way to fix the pipe if it is punctured? cheers

 

[zenonithus]

ok I have dried the wood with a hot air gun. After there was some sticky residue which I cleaned with white spirit. So the wood seems dry now. I have also put some litmus paper behind the picture rail touching the side of the nail area. I am assuming if the litmus paper has any green within a few hours or the next day then its some sort of leaking pipe or water tank from above. If the paper stays dry then my other assumption is there is a leak in the roof where rain water is getting in and soaking the wall. If it rains and the paper goes green this would be an indication of that.

This same wall I noticed when I moved in the front door architrave was completely rotten on the left side. The picture rail and kitchen door architrave run right next to the front door on the same wall as the rotten architrave. Further more when I pulled out the electrical wire cover next to the rotten front door architrave, I noticed the screws were rusted pretty bad, indicating water has been penetrating this wall for a while and maybe it is possible me adding more holes near the top gave it an outlet to seep out and have the bare wood absorb it. The only reason it wasnt noticed in the wood before was that the wood was painted heavily so the dampness wouldn't show through.

Does this all sound a bit crazy or if there is a leak in the loft can it soak the brick wall and cause this? Wouldn't I be noticing damp straight away if this was the case? Unless it is only wet when raining it could dry out before getting damp?

 

[HERTS P&D]

What you can do is draw around the damp mark with a pencil and see if it gets bigger over 24hrs, if so then you have a leak.

Or if you have a water meter then make sure no water is being used and see if the meter moves over the space of an hour.

Andy

 

[zenonithus]

Hey Andy, It was pretty much damp all along one half of the picture rail with a few dry patches here and there. I just checked the weather and the only rain is on sunday, so if the litmus remains dry until then it could be rain. If there was water seeping out the hole with the nail the paper would soak it up like a sponge and turn green. I checked it just now and there is tiny dry speckles of green though this could be due to the remaining dampness behind the rail.

Ah good point with the water. I don't actually have a water meter though I could probably check the combi boiler pressure to see if it goes down if it is connected to the heating. Still not sure why it only affects the wood. Would it not wet all that dry plaster?

 

[HERTS P&D]

Go into your loft and see if you can see day light, (with the light off).

Andy

 

[zenonithus]

yeah that's a good idea. Even if there are no large gaps that are obvious its possible the water can come from cracks, trickle and drip directly into the area. Will need to look for telltale signs of water staining or such. Would you assume looking in that area it there was a water pipe situated in the wall it would be visible in the loft as would go into a tank or something?

I guess I will need to wear a hazmat suit and respirator going up there as I think there is that thick fiberglass wool and who knows if there is asbestos?

 

[HERTS P&D]

Just look in the loft above the 'leak' showing on the wall below. Also look out at the roof for any slipped or broken tiles.

Andy

 

[zenonithus]

Will do thanks Andy. Hopefully I will find something obviouse. Really hoping it's not a leaky pipe in the wall as it will be up to the building management to fix the roof if that is the cause and less hassle for me

 

[HERTS P&D]

'building management'

Is this a flat or rented property?

Andy

 

[zenonithus]

yes its a flat, though I own a share of the freehold. They are more the property management that handle the service charge.