Potential purchase / apparent rising damp / cause for concern

[lholman]

All,

I hope you may be able to shed some light/give some advise as to my next course of action. I have recently had an offer accepted on a turn of century brick built property in East Sussex (Brighton). The property is end of terrace and it’s suspected that the main walls of the building are 9” (225mm) solid brickwork. The walls externally are rendered which are painted and conceal the wall construction meaning there is no visible insitu damp proof course.

I have commissioned two individual damp proof reports but after reading quite a few articles on this forum I am in no doubt they will all come back suggesting required work. The first report which was (strangely!) commissioned by the Estate Agent, apparently they do this as standard for the majority of period properties but my doubt is that it was done after a previous survey identified the requirement.

The main areas of concern I have, taken from both the initial two reports (awaiting detail from the last which is being completed today) and a number of viewings and inspections by my self and family are as follows. It is worth noting that the property doesn’t smell of damp and there is no visible sign of damp walls on the ground floor. It is of a standard 2 up 2 down construction with a hallway against the party wall separating the living room and party wall:

-The first report has identified through the use of a Protrim moisture meter that there is proof of rising damp and subsequent preventative damp proofing is required along all accessible areas of the party wall and some area of the internal wall between the hallway and living room. Due to cupboards and fittings in the kitchen it was not possible for the report to include the remaining stretch of the party wall into the kitchen, this is obviously of some concern as the main reason given for the rising damp is that “the adjoining property ground levels are higher than the subject property internal floor levels” this would seem to suggest that the complete length of the party wall may need preventative damp proofing is needed at all?
-The second report has not identified any remedial damp proofing required on the party wall, but has identified that the whole internal wall between the hallway and the living room needs treatment.
-One of my major concerns is as to why three walls within the Living Room are dry lined. Although this is a commonly used method to legitimate DIY’ers/Builders etc? Obviously this dry lining prevented the walls being tested internally for rising or penetrative damp during the any reports, is my only way of investigation this to do/get done a drill test? The current vendor says the walls were dry lined when he bought the property 8 years ago.
-There is also some gable end damp staining observed in both bedrooms from what seems to be ongoing and / or historical rain water penetration (according to the report). I am inspecting this separately but wonder if potentially cracked rendering on the gable end wall would amplify any potential damp problems, letting in water and trapping it behind the render.

Any views or ideas on my best method of attack would be greatly appreciated, I am under considerable pressure from the Estate Agent about moving forward with a survey which I am arguing will give me no more insight as to the (potential) damp problem on the ground floor.

Kind regards,

Lloyd

 

[Superman]

-The first report has identified through the use of a Protrim moisture meter that there is proof of rising damp and subsequent preventative damp proofing is required along all accessible areas of the party wall and some area of the internal wall between the hallway and living room. Due to cupboards and fittings in the kitchen it was not possible for the report to include the remaining stretch of the party wall into the kitchen, this is obviously of some concern as the main reason given for the rising damp is that “the adjoining property ground levels are higher than the subject property internal floor levels” this would seem to suggest that the complete length of the party wall may need preventative damp proofing is needed at all?

Remove the back of the cupboards and check with the moisture meter.

-One of my major concerns is as to why three walls within the Living Room are dry lined.

Sometimes rather than insulate an entire house, the walls of the rooms most often used (Living Room and Main Bedroom) are drylined. It might not necessarily indicate that there is a problem.

Obviously this dry lining prevented the walls being tested internally for rising or penetrative damp during the any reports, is my only way of investigation this to do/get done a drill test?

As far as I know - yes.

-There is also some gable end damp staining observed in both bedrooms from what seems to be ongoing and / or historical rain water penetration (according to the report). I am inspecting this separately but wonder if potentially cracked rendering on the gable end wall would amplify any potential damp problems, letting in water and trapping it behind the render.

Cracked render does allow damp in. Also if the render has started to come away from the wall, it will allow water to penetrate and then stand behind the render - in which case it soaks through the wall and can start to rot floor boards etc. To deal with this, one must remove the old render (if it is coming away), and rerender the facade.
Is the gable end on an exposed side of the building (facing prevailing winds)?

I would first look at things like gutters, flashings and roof slates/tiles. Is there a chimney on the gable - chimneys can cause a lot of problems? These are the most likely places to pick up problems.

Is the water staining underneath the windows? Water often comes in here.
Also check the joists of the bedrooms by jumping up and down in the room - are they softer than would be expected (indicating that rot may have set in). Do this in particular in any area where the walls are damp.

Any views or ideas on my best method of attack would be greatly appreciated, I am under considerable pressure from the Estate Agent about moving forward with a survey which I am arguing will give me no more insight as to the (potential) damp problem on the ground floor.

I'd assume that the damp problem has to be dealt with. Ask for a quotation to put in a chemical D.P.C. and figure that into your costs.

 

[lholman]

Many thanks for your time and detailed answers Superman. Please see my responses below.

Remove the back of the cupboards and check with the moisture meter.

Will do, I believe there is no back to the cupboards anyway as it's not a high end kitchen.

Sometimes rather than insulate an entire house, the walls of the rooms most often used (Living Room and Main Bedroom) are drylined. It might not necessarily indicate that there is a problem.

Thanks for confirming that, I will be a bit more constructive with my questioning then.

Is the gable end on an exposed side of the building (facing prevailing winds)?

Yes it is, its the end of terrace wall. This is North - North/West facing.

Is there a chimney on the gable - chimneys can cause a lot of problems?

There is a chimney breast on that wall but it comes up the side of the gable (I hope i'm using the correct terms here?), it is capped off at the loft and the fireplaces are not used (the living room breast is dry lined and there is a gas fire). If the stack continued out of the roof it would appear out of the roof around half way up the pitch.

Is the water staining underneath the windows?

Not to my knowledge, in all honest I didn't notice this it was picked up from the report, I will have a look when I next get a chance.

check the joists of the bedrooms

I will do, hadn't thought of this, I suppose this would give a good indication as to the extent of the problem?

I'd assume that the damp problem has to be dealt with. Ask for a quotation to put in a chemical D.P.C. and figure that into your costs.

These reports both suggest this option if checmical D.P.C is the same as injecting a chemical horizontal damp proof course? I have quotes within £50 or each other, both just shy of £1000, however they both identify opposite walls. One report recommends the party wall which they say is caused by the ground level being higher on the parties side, due to us being at teh bottom of a hill and the other suggests the opposite internal wall separating the hallway from the living room. No consistency.

 

[ludermor]

If it the property is turn of the century then it would have no ( or minimal) DPM. On the walls it probably just has a slate course and probably noting under the floor. The best job may be to get electro osmosis on all the walls and to tank the floors. It wont be cheap but it would be a proper job

 

[lholman]

Thanks ludermor, just a few more questions.

no ( or minimal) DPM

Damp Proof Membrane? II'm still not sure of the difference between that and a Course apart from the obvious natural and man-made differences.

On the walls it probably just has a slate course and probably noting under the floor

Excuse my ignorance but what is required under the floor? For your reference it is a suspended timber floor.

The best job may be to get electro osmosis on all the walls and to tank the floors.

I think I understand Osmosis as the process that negatively charges the water ions etc. so as to prevent the water (and slat) rising up the walls through a cappilary action? However I am not sure what you meen by tanking of the floors?

It wont be cheap but it would be a proper job

I am a firm believer of the "do it once, do it right" methodology and will negotiate with the vendor on that basis.

 

[Superman]

There is a chimney breast on that wall but it comes up the side of the gable (I hope i'm using the correct terms here?), it is capped off at the loft and the fireplaces are not used (the living room breast is dry lined and there is a gas fire). If the stack continued out of the roof it would appear out of the roof around half way up the pitch.

Check externally at the flashings around the chimney. Also check the top of the chimney to see if the pots are capped with lead and the caps wired down. If the chimney is made of brick, it is quite likely to allow water in - it might need to be repointed. In Ireland, because of the exposure in a number of locations, I would generally not recommend brick chimneys - plastering them is a good idea. The exposure in the U.K. might not be as bad though.

I will do, hadn't thought of this, I suppose this would give a good indication as to the extent of the problem?

It will indicate if the problem is "really serious". Just because the joists are not soft, doesn't mean the problem is not "serious", though.

These reports both suggest this option if checmical D.P.C is the same as injecting a chemical horizontal damp proof course?

Yes - that's it.

I have quotes within £50 or each other, both just shy of £1000, however they both identify opposite walls. One report recommends the party wall which they say is caused by the ground level being higher on the parties side, due to us being at teh bottom of a hill and the other suggests the opposite internal wall separating the hallway from the living room. No consistency.[/font]

I'd be more worried about the external wall than the internal one. The internal wall would only be a problem if there are springs under the house. This would be quite unusual. This would be easy to check - as both sides of the walls would show rotten skirting boards, peeling wall paper, efflorescence etc. Even if the living room walls are covered, you can check it from the hall side.

 

[Superman]

Damp Proof Membrane? II'm still not sure of the difference between that and a Course apart from the obvious natural and man-made differences.

Damp Proof Membrane is under the entire floor. The DPC is under the wall.

Excuse my ignorance but what is required under the floor? For your reference it is a suspended timber floor.

For a suspended timber floor, make sure that the ventilation is adequate. Jump up and down on the floor (to check for soft joists). (Or properly you could bore samples etc.)
Where possible, I would recommend dropping the ground externally by 6" etc. below the level of ventilation. The greater the distance between ground and floor the better.

I think I understand Osmosis as the process that negatively charges the water ions etc. so as to prevent the water (and slat) rising up the walls through a cappilary action?

That is correct. An electric D.P.C. works on the principle that one can repel these ions.

However I am not sure what you meen by tanking of the floors?

This would not apply to you, as you have a suspended floor.
Though I would check that in the Kitchen - standard 19th Century houses had solid floors to the work spaces, and suspended floors to the living spaces. It means digging up the floor, putting in a DPM, (and adding insulation while you are at it) and then repouring a concrete floor. A lot of work.

 

[lholman]

Superman, cheers for the continued answers.

I have taken all your comments from your last two responses on board and am starting to believe as you have suggested that this apparent internal wall dampness could be because of the lack of ventilation, however I know that a survey will not investigate under floor boards so assume I really just have to make an educated guess and purchase off the basis of that?

Though I would check that in the Kitchen - standard 19th Century houses had solid floors to the work spaces, and suspended floors to the living spaces.

I did check under the kitchen cabinet kick boards and there are floor boards, also the vendor said it is boarded under the laminate.

Regarding your other post and the chimney breast:

Check externally at the flashings around the chimney. Also check the top of the chimney to see if the pots are capped with lead and the caps wired down. If the chimney is made of brick, it is quite likely to allow water in - it might need to be repointed...

I don' think I explained this properly previously, the chimney stack has been lowered and left open at the loft (i.e. under roof level), it is not in use. Sorry I think I incorrectly used the word capped earlier. It does look like the roof is newer than other houses on the street and no chimney breasts are exposed through the roof.

Back on to the walls and the supposed damp problem! I agree with what you say about the internal wall and will inspect my self in more detail from the hallway side. I have one more report to follow up regarding the hallway dampness (which i'm starting to think is a bit misleading). My outstanding concerns are now that of the party wall (even though one report says there's no problem there) and the other two dry lined external walls of the living room which we can't get any idea of potential dampness from, i.e. can't investigate from the inside as they're dry lined, can't investigae from outside as they're rendered.