Penetrating Damp Source?

[BenELL]

Hi

I have had a damp problem in my front room since I moved into my house a few months ago. There had been some damage to the external face of the house but this was sorted a few months ago and I had presumed continuing problems had been due to residual damp left in the thick stone walls.

However after 2 days of solid rain, water is now beading on the wall at about 80cm above floor level, almost to the point where it is dribbling down the wall. It is in a fairly isolated area and I am struggling to identify the source of this. The water seems to be focused around a small area directly the other side of the wall to a conifer which is positioned right next to the external wall. The external walls are thick stone (180 year old house)

Photos displays this:

Could the conifer be causing this or will it be penetrating into the wall from above, I cant see any obvious signs of damage to the wall above.

Thanks for any help

Ben

 

[^woody^]

You need to look behind the tree

Most likely, the tree is catching the rain water and then directing it against the house wall where it is finding a route inside.

Trim the tree back a few inches so that it is off the wall

 

[BenELL]

Hi,

Thanks for the reply. There is no visible damage to the house behind the tree. There are a couple of hairline cracks in the masonry paint slightly above where the tree is, could these enable enough water through to penetrate the wall? This is the wall which bears the brunt of any weather.

Should I trim the hedge so it does not touch the wall?

Thanks.

 

[Nige F]

Hi,

Thanks for the reply. There is no visible damage to the house behind the tree. There are a couple of hairline cracks in the masonry paint slightly above where the tree is, could these enable enough water through to penetrate the wall? This is the wall which bears the brunt of any weather.

Should I trim the hedge so it does not touch the wall?

Thanks.

Cut the thing down to the root

 

[BenELL]

Do you think that is what will be causing problems?
I am happy to get rid, but to confirm, can water in that quantity travel 'up' the wall as the base of the tree is about a meter below where water the damp patch is?

Or will having a tree brushing alongside the external wall cause moiture ingress?

 

[^woody^]

If water is moving upwards, then it will show as a wide area near the floor and narrowing the further up the wall it goes

If as you say in the first post, the damp is about 800mm up from the floor and beading down the wall, then that would indicate that water is penetrating at 800mm or above.

So you need to look for problems at this height or higher.

That tree is a very strong contender for the cause or a partial cause. If you can bend it out the way and check the walls then you might see a problem. But if the tree is allowed to hold water against the wall then it could be causing it to penetrate in greater quantities than it otherwise would

 

[BenELL]

Thanks again for the reply.

Yeah the water seemed to be confined to an area about 300mm wide and at a height of 800mm from floor level.
There is no sign of any dmap, new or historical at a lower level than that.

I have hedgetrimmed the bush back to give clearance of about 100mm between the wall and hedge so hopefully that will help.

There were a couple of hairline cracks in the masonary paint above this level, but other than that no obvious signs of damage where water could get in. I filled the masonary cracks with exterior filler and re painted over them once dry. Can cracks like that cause ingress?

 

[tim00]

1. when you say previous damage to the front wall, what damage?

2. why have a planter arrangement so tight to the structure? The planter is trapping water. Possibly, the rendering stops below the soil level.

3. what is the purpose of the various levels and hard(flag) surfaces in the forecourt/yard? Is it to shed water?

4. how are you testing for damp? capillary action can cause moisture to easily reach 1m ht.

5. some exterior paints can trap moisture in the wall(s).

6. research the "checklists" for rising and penetrating damp on this forum, there are 10 - 15 variables that you might consider.

7. a plan view and a section view of the area concerned would help.

 

[BenELL]

1. when you say previous damage to the front wall, what damage?

The top section of the white painted detailing around the front window was broken away and exposed. This was re-rendered and re painted

2. why have a planter arrangement so tight to the structure? The planter is trapping water. Possibly, the rendering stops below the soil level.

The planter was in-situ when I purchased the house. The rendering appears to continue about 100mm below level of gravel in planter, although unpainted.

3. what is the purpose of the various levels and hard(flag) surfaces in the forecourt/yard? Is it to shed water?

In the yard there are some stone steps up to the front door

4. how are you testing for damp? capillary action can cause moisture to easily reach 1m ht.

I have not tested for damp other than viisble signs. After removing painted decoration on the inside of the wall, it appears the plaster is damp only at a height of 800mm and is about 300mm wide/100mm high. This area had small beads of water on the surface. This small area is directly the other side of the wall to the tree location (about 2/3thirds of way up eight of tree). and was worst the other day after heavy rain for a number of days. From the best I can tell this is not rising damp, there is no evidence of damp behind skirting and void under house is well ventilated with air bricks on front elevation (slightly above top of planter in white section of front wall) The plaster below this level appears visibly dry.

5. some exterior paints can trap moisture in the wall(s).

They are about 300mm solid stone walls. After observing the wall when raining it seems water is dripping heavily onto the section of wall behind the tree. Could the tree itself be preenting the wall from drying out too? As a short term solution I am hoping that having a 100mm clearance between tree and wall should help this. Longer term it may be I have to remove the tree and render the top of the planter with a slope away from house?

6. research the "checklists" for rising and penetrating damp on this forum, there are 10 - 15 variables that you might consider.

Thanks I will have a look

7. a plan view and a section view of the area concerned would help.

I will make a sketch and upload later.