Rough cost of replacing old rendering

[MartinB85]

Hi Guys,

We've had issues with penetrating damp for a while (Roof replaced, guttering, chimney pointing/lined to try and fix it). Basically there are water streaks running from the top of one wall in the bedroom. I've had advice from the roof guys who came back to check the roof (which they advised was fine and dry) that it must be coming through the rendering been hit by the rain, a damp solutions company also gave me the same advice after looking at all the work we've had done.
To cut a long story short I am wondering what price I should be looking at to have the side wall done its around 14sqmts as its only the top half of the house. Ideally I want the most long term water-proof solution.
Any advice would be great, cheers.

 

[Alastairreid]

Doubt its the roughcast if its running from the top of the wall.
post a pic of the dampness if you can.

 

[MartinB85]

Doubt its the roughcast if its running from the top of the wall.
post a pic of the dampness if you can.

Hi,

Sorry for the delay, due to the colour if the paint it’s quite difficult to see properly on the pictures.
The water marks run to the left side of the chimney breast and then you can see the shine of the water along the top of th wall when it rains and then the rest of the wall just had darker patches here and there. Sorry for the difficult pics!

I’ll try get up the ladder and take some close up pics of the render today.

Thanks

 

[Alastairreid]

Where is the chimney breast in relation to those pics?

 

[MartinB85]

Where is the chimney breast in relation to those pics?

Its to the right of where the drips are appearing on the wall, bang in the middle of our bedroom wall. We’ve got a cap on the chimney that allows air flow but stops rain getting in.

I’ve added a few photos of the roughcast on the surface it looks ok no real cracks, unless it can hold water in and penetrate it. The house is 100 years old so unsure how long its been on for.

 

[Alastairreid]

Looks like the roof and chimney have been well covered, tidy work.
My next thought would have been the eaves, under the tiles but that all looks good.
Rainwater would not normally reach up to the soffit with that oversail.

Its an external wall with a chimneybreast..probably a cold wall and susceptable
to condensation! have you considered this?.

 

[MartinB85]

Looks like the roof and chimney have been well covered, tidy work.
My next thought would have been the eaves, under the tiles but that all looks good.
Rainwater would not normally reach up to the soffit with that oversail.

Its an external wall with a chimneybreast..probably a cold wall and susceptable
to condensation! have you considered this?.

I did think about condensation but the issue only arises during decent rainfall. I did originally go in the loft and found condensation but thats because I used kingspan boards in the loft so got rid of those a few weeks ago and I’ve started to reinsulate with sheep wool insulation.

So I was hoping that was the cause but 4 weeks later it was bone dry in the loft but still coming through the wall when it was throwing it down.

I’d assume condensation would be worse when the house temp is up and its cold outside not when its gishing it down?

Would it be worth taking off the plaster and getting some to use a membrane on the inside and replastering, I just don’t want to move the problem elsewhere.

The living room below us is fine.

 

[Alastairreid]

Are both of the flues getting used?
Is there a defunct flue in the bedroom that is closed off and unvented.

 

[roy c]

When it rains does it come over the gutter on the back of the chimney? It looks like the lead on the chimney needs beating to the shape of the gutter! Have a look when you get a rainy day. It might be running over and going under the soffit. Also the other side of the chimney looks like the tiles should of been cut a bit more as there is not much room between the chimney and the tiles could of done with a bit more room between chimney and tiles to let water run off straight away! Depends how good their lead work is around chimney and back of stack! That's where I think the problem may be.. Find a good reputable plumber who does lead work to check the lead work out for you.. Also I would put some silicon in the gap between the soffit and top of wall, where there is a gap between the two of them..

 

[MartinB85]

Are both of the flues getting used?
Is there a defunct flue in the bedroom that is closed off and unvented.

There is a flue for the bedroom, we’ve only been in the house 2 years, but pretty much sure its been blocked up for quite some time we just have a rain proof cap on the pot. The other flu we recently had lined with thermocrete.

 

[MartinB85]

When it rains does it come over the gutter on the back of the chimney? It looks like the lead on the chimney needs beating to the shape of the gutter! Have a look when you get a rainy day. It might be running over and going under the soffit. Also the other side of the chimney looks like the tiles should of been cut a bit more as there is not much room between the chimney and the tiles could of done with a bit more room between chimney and tiles to let water run off straight away! Depends how good their lead work is around chimney and back of stack! That's where I think the problem may be.. Find a good reputable plumber who does lead work to check the lead work out for you.. Also I would put some silicon in the gap between the soffit and top of wall, where there is a gap between the two of them..

Thanks for the advice regarding the lead, its pretty difficult to get onto the roof with the ladders I have so I might get someone round to take a look at the back guttering.

I’m not sure of the full ins and outs of the roof but if it wasn’t draining would I not be able to see water running down the brickwork of the chimney in the loft. i can see about 2/3 rows of stack and originally water was trickling down the bricks but since the pointing I’ve seen no more water in the loft and now the whole area is bone dry. (Attached a photo of the prev issue)

I suppose I could just hose behind the chimney for a while just to see if I get any droplets appearing again.

 

[Alastairreid]

You need a vent in the room where the old flre opening used to be.

 

[MartinB85]

You need a vent in the room where the old flre opening used to be.

We plan on replacing the plaster on that wall but wanted to make sure we had fixed the issue first so i’ll make sure we put one in when we do. If it was an airflow issue would the issue not be present where the stack is as well and not to the side of it?

 

[MartinB85]

You need a vent in the room where the old flre opening used to be.

Just to give you an idea the pic below shows the build of our flues. The left flue is now a solid thermocrete (concrete) flue that we use and nothing can get through it. The majority of the water when raining is present to the left of the stack. It drips down the wall, there isnt much to the right of the stack where the flue for the bedroom goes up. The water does run along the whole top of the wall there just isnt enough for it to run down apart from on the left.

 

[MartinB85]

Roof guys came round and had a look at the lead, it's only holding a really small bit of water behind the stack, the majority drains away as expected. A lot of the holes in the air brick were siliconed up and full of dirt so I've cleaned those out. It looks like we do have cavity wall insulation, i'm unsure we have it on the gable end where the water issue is, but i've heard that if a wall is susceptible to cold, wind and rain that cavity insulation can cause issues as well.

I'll be putting in an airbrick into the flue, and we have 2 surveyors coming round so hopefully we can get some answers.