surveyor's comments about extension

here_we_go

I am (an FTB) reading the Building Survey that I commissioned, and trying to work out how serious the issues raised are.

This is a late Victorian house, with a small single-storey extension (the corner of a larger room) estimated to be 5 years old. The surveyor has bad things to say about this extension.

It does not have Building Regulations. I understand I could ask the vendor to pay for insurance against the Council taking action on this (which would probably be cheap), but not against the work being of poor quality.

More seriously, the surveyor says the extension is "generally of a poor standard of construction". Specifically, it is believed that no damp course is fitted to the walls or floor, which is considered "poor detailing". (The extension is cavity brickwork or blockwork, and has a solid floor.)

High levels of damp were detected (with a protimeter) above skirting level, and it is suggested that this is serious because of the extension's methods of construction. Some posters in this forum have been scathing about the value of damp meters; would they stick to that line in this case, despite the points about the method of construction?

For comparison, high levels of damp were also detected at a ground storey location in the original part of the house. (The original house is solid brickwork without a damp course, and has suspended timber floors.)

I plan to phone the surveyor to see if they can put a bit more colour on their opinions about the extension, but thought I'd take some soundings here first.

So, basically: Are the damp readings a real issue? And is the more general point about poor construction a real issue? Or is my surveyor just giving me ammunition to negotiate a lower price (which they do suggest)?

The original external walls were removed as part of the extension, so adequate support for the walls directly above at first floor level is clearly vital. However, the surveyor did not notice significant movement in the main walls anywhere in the house.

LHW99

My understanding is that protimeters effectively are "dry meters", in that they confirm if a wall has no problems because it is dry. Getting a reading could be due to a DPC issue - or to that being a cold wall, or on a weather exposed corner or from bridging of the cavity for example.
I would question how the surveyor could determine there was no DPC in the floor, since mosdt of them refuse to lift carpets etc, and any DPC would be likely to be below a screed.
In the original house, with brick + timber floor, you would expect air bricks or similar to provide ventilation below the floor level.
Insurance against the coucil taking action re the building regs is something to think about, but IMO if you buy an older house, these sort of issues crop up - and newer houses have different ones, but they have them just the same. What does the paint / wallpaper look like in the diagnosed area(s)?

Davesnave

It seems incredible that anyone would build a cavity walled extension in recent times without incorporating a DPC in the brickwork and a DPM in the floor, because the cost of these would be negligible and their incorporation basic sound practice.

One would be bound to ask, what sort of builder would do that and whether they could be trusted to ensure adequate long term support for the opening they created, presumably without the advice of of a structural engineer? My answer would be 'No.' The general conclusion that the extension is poorly constructed bears this out.

This goes beyond the arguments about damp meter use and abuse; the construction sounds like a lash-up. Far from providing extra value and an asset, it could well be a liability and needs treating as such.

I'd seriously consider walking away. If the seller has allowed this to happen and been complicit in avoiding building regulations and control, one wonders what other surprises remain hidden.

here_we_go

There is no visible sign of damp affecting paint / wallpaper. Just the meter readings.

The extension's floor is tiled, and tiles weren't lifted for the survey.

The original house does have air bricks. (And I'm told is unlikely to have a DPC due to date of construction.)

here_we_go

Davesnave wrote: »

This goes beyond the arguments about damp meter use and abuse; the construction sounds like a lash-up. Far from providing extra value and an asset, it could well be a liability and needs treating as such.

I'd seriously consider walking away. If the seller has allowed this to happen and been complicit in avoiding building regulations and control, one wonders what other surprises remain hidden.

Yes, this is my larger concern.

FreeBear

here_we_go wrote: »

High levels of damp were detected (with a protimeter) above skirting level, and it is suggested that this is serious because of the extension's methods of construction. Some posters in this forum have been scathing about the value of damp meters; would they stick to that line in this case, despite the points about the method of construction?

If used correctly and with an understanding of the variables that affect the readings, they can be useful in indicating where there might be damp. Trouble is, many surveyors stick them in a wall, see a reading, and without any understanding, declare a wall is suffering from "rising damp".

In your situation, the surveyor has identified a number of faults with this extension (lack of DPC, poor build quality), and is suggesting that there are problems with damp.

I suspect that he would recommend demolition and rebuilding with proper building control approval - It may well work out cheaper than trying to fix the faults and also improve the value of the property.

edgex

LHW99 wrote: »

My understanding is that protimeters effectively are "dry meters", in that they confirm if a wall has no problems because it is dry. Getting a reading could be due to a DPC issue - or to that being a cold wall, or on a weather exposed corner or from bridging of the cavity for example.
I would question how the surveyor could determine there was no DPC in the floor, since mosdt of them refuse to lift carpets etc, and any DPC would be likely to be below a screed.
In the original house, with brick + timber floor, you would expect air bricks or similar to provide ventilation below the floor level.
Insurance against the coucil taking action re the building regs is something to think about, but IMO if you buy an older house, these sort of issues crop up - and newer houses have different ones, but they have them just the same. What does the paint / wallpaper look like in the diagnosed area(s)?

I assume this extension has external walls, & the surveyor has looked at those & found no evidence for a DPC.
They are usually obvious, as the mortar layer is thicker.

Cakeguts

Find a different house where there isn't an extension that sounds as if someone who has no experience of building extensions has built one. If they do this with an extension you can be sure that they will have done lots of other things to the house that are not well done.

Doozergirl

I can't be bothered to quote properly but "Some posters in this forum have been scathing about the value of damp meters; would they stick to that line in this case, despite the points about the method of construction?"

No, I would not stick to that line in a five year old extension with no visible DPC. I too would be primarily concerned about the build quality and agree with everything that Davesnave and FreeBear have said.

Contrary to what someone else has said, you would see the DPC outside. You just wouldn't see a DPM inside without removing a skirting board.

It's a damp proof course (DPC) between the bricks and a damp proof membrane (DPM) under the floor, lapped over the DPC.

Owain_Moneysaver

Who would build an extension these days without Building Control approval?

Doozergirl

Owain_Moneysaver wrote: »

Who would build an extension these days without Building Control approval?

Someone asking on the In My Home board this morning if it was okay. :eek:

In fairness, they were worried but their 'builder' clearly wasn't. :mad: