Buying a House with Damp
- Buying a house with damp can be safe, as long as the problem isn't severe.
- Damp can devalue your property, so it is important you get a survey before making your purchase.
- It's important to get a survey to check for this, as signs of rising damp may take years to appear.
- If the problem is complex, you can either ask the seller to remedy the problem or renegotiate your offer.
Rising damp, whether in your home or a rental property, is a challenge that needs addressing. The signs range from mouldy walls to condensation and the damage that can be caused is considerable. If you are concerned you have damp then you'll need to instruct Damp Specialist Surveyors to assess the property. Damp surveys range it cost from £264 INC VAT upwards depending on the size of your property and you can even get a damp and timber survey at the same time.
In this article we examine:
- How serious is damp in a house?
- How much does damp devalue a house?
- What are the main issues that cause it?
- Do house surveyors check for damp?
- How much does damp proofing cost UK?
- How do surveyors check for damp?
Would damp put you off buying a house?
Buying a house with damp does not have to be too concerning, depending on the severity of the problem. We always recommend getting a survey to check for signs of rising damp. We have local damp specialist surveyors through England, all PCA registered (Property Care Association).How serious is damp in a house?
Bricks, mortar or sandstone, being porous materials, draw water naturally from the ground (moisture) and absorb it. Builders use damp proofing to protect against this happening by building in a non-porous layer of material which separates the bricks/mortar/sandstone from the ground, stopping the water being absorbed.
Problems occur when this damp proofing either isn't present or has become damaged. This is made worse because if you're buying a house with damp, the signs of damp rising may not appear for a few years.
By the time these signs appear, the porous material/s will have become damp and moist and require speedy attention.
- Damaged internal decoration – Damp or discoloured tidemarks on internal walls;
- Damaged plaster – Disintegration, salting or blistering;
- Rotting skirting boards or floor boards – wet rot with decay;
- Localised dampness – Dampness on walls rarely exceeds one metre above ground level, but may go much higher in extreme cases
How much does damp devalue a house?
This depends on the extent of the problem and the type of damp (whether it's condensation, penetrating damp, or rising damp). The latter is the most damaging. It can cause a property's value to drop by at least 10%.What are the main issues which cause damp to rise?
The main factors causing the problem are:
- Existing damp proof no longer works.
- No damp proof ever laid.
- Ground outside the external wall is higher than damp proof.
- Internal plastering bridges the damp proof course.
- Build up of rubble inside a cavity wall bridges the damp proof course.
- Previous penetrating damp issue has left residual damp at the base of a wall.
- Poor circulation causes condensation at the base of a wall.
- Leaking water pipes at the base of the wall.
These are typical and general signs of rising damp but you must get an expert to test the wall involved to confirm the condition. A RICS Surveyor tests for damp using a damp meter during a HomeBuyer Report or a Building Survey.
Do house surveyors check for damp?
If your RICS Surveyor suspects that a property suffers from rising damp, you should book a Rising Damp Surveyor to inspect its internal, external walls and floor boards. They test for visible signs of moisture using a moisture meter. The final check is to take a sample from the porous material to find out how damp it is. They get this by drilling into the wall.
RICS Surveyor and builder Jeff Howell recently wrote that a damp meter can detect other atmospheric conditions which may not be relevant and therefore you must book a full Damp Survey before you pay out lots of money for new damp proofing. Chemical injection of damp proofing is advised in around 5,000 UK weekly - which costs more than £200 million per year - and much of this is because of the widespread misuse of electrical moisture meters.
Jeff also confirmed investigations into other types of damp proofing such as electro-osmosis and atmospheric siphons (eg Wallguard, Schrijver Systeem and Holland Damp Proofing). He has stated that these remedies are often mis-sold to the British public too.
If you have rising damp you can get it fixed but you are strongly advised to get a Damp Specialist to confirm you have the condition first.
How much does damp proofing cost UK?
Problem | Solution | Terraced House – One Wall | Terraced House – Whole House | Semi-Detached House – One Wall | Semi-Detached House – Whole House | Detached House – One Wall | Detached House – Whole House |
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Problem Ground level is above the existing damp proof course | Solution Excavate soil only | Terraced House – One Wall £204 | Terraced House – Whole House £268 | Semi Detached – One Wall £262 | Semi Detached – Whole House £594 | Detached House – One Wall £437 | Detached House – Whole House £1,456 |
Problem Ground level is above the existing damp proof course | Solution Excavate soil and lay pre-cast concrete paving slabs | Terraced House – One Wall £431 | Terraced House – Whole House £728 | Semi Detached – One Wall £600 | Semi Detached – Whole House £1,491 | Detached House – One Wall £1,036 | Detached House – Whole House £3,274 |
Problem No damp proof course in wall | Solution Inject silicone damp proofing course | Terraced House – One Wall £221 | Terraced House – Whole House £350 | Semi Detached – One Wall £384 | Semi Detached – Whole House £769 | Detached House – One Wall £600 | Detached House – Whole House £1,899 |
Problem Internal walls are damp | Solution Asphalt tanking to 1.2m height and decorate to full height | Terraced House – One Wall £1,631 | Terraced House – Whole House £3,250 | Semi Detached – One Wall £2,435 | Semi Detached – Whole House £6,477 | Detached House – One Wall £4,858 | Detached House – Whole House £15,366 |
These quotes come from the Royal Institution of Chartered Surveyors’ Building Cost Information Service (December 2011).
If you think you have damp rising and your RICS Surveyor also has suspicions of the issue, book a Damp Survey from a Damp Specialist, wait for the Damp Survey to come back and only then take action.
If you haven’t bought the property and the damp survey is conducted while you are doing your due diligence, speak to the seller and negotiate a reduction in the purchase price to account for the costs you are going to incur. This is entirely fair because the damp will have been worsening during their ownership.
How do surveyors check for damp?
Example Damp and Timber Survey
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