Damp Proof Course 'renewal' - how much
Discussion
Am looking at buying a house at the moment and the survey says that the dpc or plaster spec on one of the walls may be suspect. Does anyone know whether I should be able to just have that wall 're-treated' or whether it would have to be the whole property, and how much the work would be likely to cost (the wall in question is about 15-20 feet long)
cheers
cheers
just had a quote for something that sounds similar on a property i'm looking at.
It there is damp in the wall above the DPC, and its bad you will probably have to have the plaster removed and replaced with either new plaster or preferably a waterproof render , then skim.
the DPC can be replaced with a chemically injected DPC which is very easy and unobtrusive, and not too expensive.this part will probably cost somewhere around £750, althoug if you add on the replastering, will be nearer £1700 i would think if yo hget a specialist to do the work.
It there is damp in the wall above the DPC, and its bad you will probably have to have the plaster removed and replaced with either new plaster or preferably a waterproof render , then skim.
the DPC can be replaced with a chemically injected DPC which is very easy and unobtrusive, and not too expensive.this part will probably cost somewhere around £750, althoug if you add on the replastering, will be nearer £1700 i would think if yo hget a specialist to do the work.
I won't speculate on how much it will cost as I haven't done any damp proofing for a while but I would advise that if the DPC has failed in a particular area of the property you get the whole ground floor treated as the chances are the remainder will fail in the near future.
This will also provide a more robust warranty should there be any moisture penetration in the future.
This will also provide a more robust warranty should there be any moisture penetration in the future.
The problem is with any rising damp, that even if you stop the damp rising the original problem will probably have left salt deposits in the brick work
This isn't actually a real problem, apart from some damp meter will show signs of damp even if there isn't any water
To check if this is your problem, you'll need a lab test on a brick sample. It could be worth getting this done as any new DPC won't get rib of theis problem
This would also show up definitively whether you have a damp wall or not
then you have the option of a chemical or mechanical DPC, and the various plaster options. I would consider "dot and dabbing" plasterboard rather than a float and set if you do have a salt problem as when you come to sell the place a surveyoer will only bung a meter on the wall and that way your virtually gauranteed a dry reading
HTH
This isn't actually a real problem, apart from some damp meter will show signs of damp even if there isn't any water
To check if this is your problem, you'll need a lab test on a brick sample. It could be worth getting this done as any new DPC won't get rib of theis problem
This would also show up definitively whether you have a damp wall or not
then you have the option of a chemical or mechanical DPC, and the various plaster options. I would consider "dot and dabbing" plasterboard rather than a float and set if you do have a salt problem as when you come to sell the place a surveyoer will only bung a meter on the wall and that way your virtually gauranteed a dry reading
HTH
depends what they mean by "may be suspect". Do they mean there is damp, or that the property may be prone to it in the future? What type of DPC is there at the moment? Be a bit wary of the silicon injection method - it does have its place but is not necessarily the fix-all solution that many damp-proofing firms would have you believe. First thing to do is establish exactly what is causing the damp, as it can often be due to condensation from lack of ventilation, failing mortar, damaged brickwork, faulty guttering, outside ground level. All of these are generally easy and cheap to resolve, though if this were the case your surveyor would probably have noticed. There is a mine of information at www.diynot.com if you do a search for damp.
Steve
Steve
so maybe it isn't damp at all, just a reading from some duff plaster/salt deposits. There is a dpc in place, but readings on the survey suggested there could be a problem.
Maybe we should just use it as a negotiating point, then keep track on whether there are any problems once we move in?
Maybe we should just use it as a negotiating point, then keep track on whether there are any problems once we move in?
zebedee said:If you like the house there is no reason not to buy it. However the house will be valued effectively with all the work completed, so yes use it as leverage for the price
Maybe we should just use it as a negotiating point, then keep track on whether there are any problems once we move in?
we had a similar point raised on our survey, was down to
(a) a patio that was too high
(b) an attempt at a French drain that was created with a solid (concrete) floor instead of allowing free drainage
(c) the t
t that owned it before diverting the drain pipe for the entire roof into the defective french drain described in (b)
in the end we removed the problem caused by (c) and are keeping an eye on the damp.
(a) a patio that was too high
(b) an attempt at a French drain that was created with a solid (concrete) floor instead of allowing free drainage
(c) the t
t that owned it before diverting the drain pipe for the entire roof into the defective french drain described in (b) in the end we removed the problem caused by (c) and are keeping an eye on the damp.
Ime a brickie by trade and if i was to buy a place where the DPC(Damp proof Course)membrane failed i would investgate the area first by removing a few bricks on the outer skin to check to see if the cavity was clean and clear atleast 150mm (2 course of bricks) below DPC.
Ive heard these injection methods can fail and to be a 100% sure damp never returned i would 1/clear the cavity 2/install an airbrick every couple of meters and 3/cut out a couple of feet of brickwork at a time and bed in some DPC then brick up where you have cut out,the trick here is to make sure you fill in the bed joints properly to avoid cracking of the upper brickwork and wait till the area has thoroughly gone off before you do the next section and roll out the DPC membrane.
The problem with old houses are the old DPC membranes were made of bitumen and they deteriorate after a while,before this slate was used and some houses didnt even have a DPC fitted,the new membranes are like a very strong plastic.
Ive heard these injection methods can fail and to be a 100% sure damp never returned i would 1/clear the cavity 2/install an airbrick every couple of meters and 3/cut out a couple of feet of brickwork at a time and bed in some DPC then brick up where you have cut out,the trick here is to make sure you fill in the bed joints properly to avoid cracking of the upper brickwork and wait till the area has thoroughly gone off before you do the next section and roll out the DPC membrane.
The problem with old houses are the old DPC membranes were made of bitumen and they deteriorate after a while,before this slate was used and some houses didnt even have a DPC fitted,the new membranes are like a very strong plastic.
I'd be tempted to get the surveyor to elaborate as to what is meant by "may be suspect" - does it look iffy or is there just a high reading on the damp meter?
On a flat we bought a while back, the survey came back with "rising damp" in the walls and a recommendation for a new chemical dpc.
Further investigation by a damp specialist revealed that the surveyor was talking out of his ar$e.
For one, although it was a ground floor flat, the walls in question were at least 6 ft above exterior ground level, more like 12ft if you count the light well to the basement flat. Secondly, the specialist analysed the type of plaster in the affected rooms and determined that it was the wrong sort for solid stone Victorian walls and was actually absorbing moisture from the air, giving a high reading.
Of course, the mortgage company slapped a huge retention on the completion monies until the recommendations of their surveyor (i.e. a new dpc) were implemented. Despite giving them a copy of the specialist's report, they insisted, so we ended up having to wreck and re-plaster almost every room in the property for no good reason
On a flat we bought a while back, the survey came back with "rising damp" in the walls and a recommendation for a new chemical dpc.
Further investigation by a damp specialist revealed that the surveyor was talking out of his ar$e.
For one, although it was a ground floor flat, the walls in question were at least 6 ft above exterior ground level, more like 12ft if you count the light well to the basement flat. Secondly, the specialist analysed the type of plaster in the affected rooms and determined that it was the wrong sort for solid stone Victorian walls and was actually absorbing moisture from the air, giving a high reading.
Of course, the mortgage company slapped a huge retention on the completion monies until the recommendations of their surveyor (i.e. a new dpc) were implemented. Despite giving them a copy of the specialist's report, they insisted, so we ended up having to wreck and re-plaster almost every room in the property for no good reason
I bought a house with damp and it cost about £400 to have an injected DPC put into all of the walls.
I also had to have the plaster removed from about 1 metre above floor level downwards on the walls to be injected.
You then need to get the wall re-rendered and there is an additive that gets put into the mix that makes the render damp proof.
Then you need to have the wall re-skimmed ensuring that the re-skimming and re-rendering leave a small gap at the bottom (behind where the skirting will go) to stop the damp bypassing the new DPC.
I would be looking for at least £1,000 off the price if you are considering getting the work done.
I also had to have the plaster removed from about 1 metre above floor level downwards on the walls to be injected.
You then need to get the wall re-rendered and there is an additive that gets put into the mix that makes the render damp proof.
Then you need to have the wall re-skimmed ensuring that the re-skimming and re-rendering leave a small gap at the bottom (behind where the skirting will go) to stop the damp bypassing the new DPC.
I would be looking for at least £1,000 off the price if you are considering getting the work done.
Treat 'damp problems' on a survey with a very large pinch of salt. They usually poke a meter designed for measuring damp in wood, into a plaster wall, which gives the wrong readings.
What type of house is it? Suspended timber floor? Side of a hill?
If its an old house, chances are the DPC was installed unnecessarily, and its been rendered incorrectly, or pointed with cement, or plastered with gypsum. It may even be damp because the windows are all DG and shut all day!
Most damp is cured easily enough with ventilation.
/btw - most propertires don't need a DPC - just good old fashioned building materials and a good breeze. When you buy an old house and the chimnies are sealed up, its no wonder its going to get damp.
>> Edited by parrot of doom on Wednesday 5th October 13:35
What type of house is it? Suspended timber floor? Side of a hill?
If its an old house, chances are the DPC was installed unnecessarily, and its been rendered incorrectly, or pointed with cement, or plastered with gypsum. It may even be damp because the windows are all DG and shut all day!
Most damp is cured easily enough with ventilation.
/btw - most propertires don't need a DPC - just good old fashioned building materials and a good breeze. When you buy an old house and the chimnies are sealed up, its no wonder its going to get damp.
>> Edited by parrot of doom on Wednesday 5th October 13:35
The surveyor may just have spotted salt deposits on a wall - we had this, it looks like rising damp so I called out Rentokil who as well as killing nasties also do damp protection work. Their surveyor came out free of charge, took readings, drilled samples from walls (very small holes so easily filled and not too disruptive to the decor) and confirmed that there was no damp problem it was just that - salts coming out of very old plaster. He then provided us with a written report confirming their findings.
I would advise getting a specialist in to check it out - surveyors are notorious for covering their a**e and convincing you that their might be all sorts of problems so that you can't sue them for missing things later on!!
I would advise getting a specialist in to check it out - surveyors are notorious for covering their a**e and convincing you that their might be all sorts of problems so that you can't sue them for missing things later on!!
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