Extensions including garage conversions will usually require supplementary damp proofing to be installed as part of conversion, as the existing garage will typically have a single skin design for walls and floors, which was not manufactured to conform to building regulations for habitable rooms. This damp proofing will need to be put into walls and floors. Moreover, the roof of the garage conversion will require water proofing. The damp proofing of the floor of the garage conversion will most likely be achieved by by using a damp proof membrane. This membrane will come in either solid or liquid form. The damp proof membrane will be placed down either on top of the pre-existing concrete floor, below the new floor, or as part of both, depending on whether the floor will be a solid or a floating floor. In a few garages, the walls have been damp proofed, but this might need to be updated as part of the conversion to be able to meet current building regulations. The walls should be damp proofed in order to safeguard the brickwork from rotting slowly as moisture sets in. This is performed by either utilising damp proof membranes, waterproof rendering, or cavity insulation, depending on the type of walls that are already in the garage. Damp proofing is an integral part of the building regulations that the garage conversion should adhere to, and so is it vital to ensure that your garage conversion makes use of appropriate damp proofing methods.
The average cost of Damp proofing is £1500. Costs vary based upon the materials and the organisation selected. The upper price range can be as high as £1725. The material costs are in general about £375
| Avg. price low | Avg. price low |
|---|---|
| Avg. price | Avg. price |
| Avg. price high | Avg. price high |
£1900
£1425
£950
£475
£0
| Labour cost | £1,050 | |
| Material cost | £375 | |
| Waste removal | £75 |
Requests for quotations in Cornwall in June 2026
Requests for Damp proofing quotations in Cornwall in June 2026. 0% change from May 2026.
Requests for Damp proofing quotations in South West in June 2026. 0% change from May 2026.
Hello and welcome to my page. We are a Family run building business with over 20 years in the building industry. We offer a verity of services this includes: Damp proofing specialists, Bricklaying Landscaping Groundwork’s/ drainage Roof repairs Poi...
Knowledgable about the problem.
Penzance - TR18
Enquiry from: Peter L
Start Date: Immediate
(1) Repair of defective tanking in toilet in back extension on ground floor (2) Treatment of rising damp in wall of laundry room in basement
Penzance - TR18
Enquiry from: Nader G
Start Date: Immediate
i have a small damp patch at the entrance to the house on the inside. i’d like a survey to find out how to permanently fix this. i’d like a quote first are you the property owner: owner of the pro...
Redruth - TR15
Enquiry from: Tina M
Start Date: Immediate
the property has a damp problem especially on the left side of the house. the wall is soaking wet are you the property owner: relative of owner how many rooms do you need damp proofing: 3-4 rooms prop...
Redruth - TR15
Enquiry from: Lisa Z
Start Date: Immediate
hi, i have white mould just a small section in my loft. due to the air vent coming loose. please can you quote me on putting vent back and mould please. i have images as i have had a homebuyers survey...
Penzance - TR20
Enquiry from: Sarah M
Start Date: Immediate
I am in process of completing on a granite cottage in Perranuthnoe. The survey has identified a damp issue, resulting from the external wall being built higher than the internal. The best solution see...
Launceston - PL15
Enquiry from: Ben W
Start Date: Immediate
Good morning, I require a damp and timber survey to be completed for mortgage purposes. Is this something you can provide? Ben
Camborne - TR14
Enquiry from: Lisa H
Start Date: Immediate
Idea of where damp is coming from
Helston - TR13
Enquiry from: Mick S
Start Date: Immediate
Damp walls some of which are back to earth
Wadebridge - PL27
Enquiry from: Christine J
Start Date: Immediate
a cottage in chapel street I’ve had a survey done and they’ve said there’s rising and penetrating damp . I would like to know how much it would be to fix this. Thanks
Helston - TR13
Enquiry from: Sophia G
Start Date: Immediate
a flat needs a damp survey to try and resolve the issue, i do not know if this is a flat issue or buildng would this be able to be determined please
Marazion - TR17
Enquiry from: John G
Start Date: Immediate
small section of rising damp requiring injection
Bude - EX23
Enquiry from: Kym H
Start Date: Immediate
Full Apartment review, ongoing discussions with the block management, we believe damp is coming from outside the property, causing issues inside, but Plymouth Block Management is stating the cause is ...
Helston - TR13
Enquiry from: Mike C
Start Date: Immediate
Damp proof on the front wall of building Also timber treatment loft and stairs
St. Ives - TR26
Enquiry from: Lisa F
Start Date: Immediate
Identify issue in lower floor room and recommend treatment. Currently no mould, but damp musty smell.
Launceston - PL15
Enquiry from: Faith J
Start Date: Immediate
The ground floor rear of this property is below ground level and has penetrating damp. We would like to find out the cost of fixing this. Keys for survey access are available from Webbers Estate Agent...
Liskeard - PL14
Enquiry from: Marcus P
Start Date: Immediate
property under probate, initial inspection shows water ingress into kitchen likely through chimney but not sure. causing mould to grow and floorboards to warp. would need urgent remediation to secure....
Launceston - PL15
Enquiry from: Diane B
Start Date: Immediate
Damp analysis and diagnosis.
Wadebridge - PL27
Enquiry from: Erdin B
Start Date: Immediate
Full Damp work protection of the property, this may include installing a new Damp course, internal Render removal, Drying
Penzance - TR20
Enquiry from: Tamsin B
Start Date: Immediate
Assessment and damp proofing of traditional stone wall in Annexe
St. Ives - TR26
Enquiry from: Miles A
Start Date: Immediate
survey and quote required for probable damp proofing please. are you the property owner: owner of the property how many rooms do you need damp proofing: 3-4 rooms property type: semi detached please ...
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Signs of rising damp tend to be close to the ground, usually no higher than a metre. It usually works its way up walls in horizontal lines. Penetrating damp usually develops in patches and can often be much higher up. For more advice, speak to a damp proofing professional.
Damp is a serious problem, particularly if you live in an old property, because it can lead to structural damage. This will cost you big money and could be very dangerous, to yourself and the property. Take damp seriously and get it inspected and resolved as soon as you discover it!
You should make sure that all signs of damp have gone before you redecorate your walls. If you want to paint your walls with a water-permeable emulsion paint, you can usually do this after 1 or 2 months. For other types of decoration you should wait longer.
There are a few visible signs of damp, although it often goes undetected. However, in older or empty properties, this made become detectable through its smell. These include peeling paint and wallpaper, crumbling plaster, mould growth, black spots or spores on walls and ceilings, and rotting skirting boards and flooring.
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