Damp is one of the most common problems in older York housing stock, and it's also one of the most misdiagnosed, since rising damp, penetrating damp and condensation all look similar at first glance but need completely different fixes. Treating the wrong one doesn't just waste money, it can leave the actual problem to get worse.
RW Builders deals with damp proofing and drainage as part of both new extension work and repairs to existing York homes, and we start every job by working out what's actually causing the problem rather than assuming.
A lot of damp problems we're called to are actually condensation being mistaken for rising damp, which means the wrong treatment has sometimes already been tried before we're asked to look at it.
Rising damp – groundwater drawn up through a wall by capillary action, usually because the original damp-proof course has failed or was never installed, common in older properties. Typically treated with a chemical damp-proof course injection and replacement of affected plaster.
Penetrating damp – water getting in from outside, often through damaged pointing, defective render, blocked guttering, or a leaking roof. The fix here is addressing the source, not the symptom, since injecting a DPC won't solve a leaking gutter.
Condensation – moisture from everyday living (cooking, showering, drying washing) that has nowhere to escape, often made worse by poor ventilation or cold spots on external walls. This needs improved ventilation and insulation rather than a damp-proof course at all.
A lot of the damp problems we investigate are in solid-walled Victorian and Edwardian houses across York, which were built without a cavity and often with a much simpler damp-proof course than modern standards require, if one was fitted at all. These properties can be more prone to rising and penetrating damp than newer housing, but they're also more likely to suffer condensation problems if they've been retrofitted with modern double glazing and better draught-proofing without matching improvements to ventilation, since the airflow that used to carry moisture out through gaps around old windows and doors no longer exists. Treating a solid-walled period property the same way as a modern cavity wall house is a common source of ongoing damp problems, which is why we assess the construction type properly before recommending a fix.
For new extensions, proper drainage around the foundation is built in from the start, directing surface water and groundwater away from the building rather than letting it sit against the foundation walls. This typically includes:
For existing properties, poor drainage around the foundations is a common cause of penetrating damp at low level, particularly where ground levels have crept up over the years (sometimes from repeated patio or driveway resurfacing) above the level of the damp-proof course, effectively bridging it.
Depending on the diagnosis, work can include:
Investigation, including moisture readings and identifying the actual cause rather than just the symptom
Chemical damp-proof course injection for genuine rising damp
Repointing or render repair for penetrating damp caused by failed brickwork or render
Re-grading external ground levels or installing a land drain where ground level has bridged the DPC 5. Replacing affected internal plaster, since damp-affected plaster generally needs to come off rather than be redecorated over
Improved ventilation, including extractor fans or trickle vents, where condensation is the underlying cause
Damp-proofing work on an existing house doesn't generally require planning permission, since it's treated as repair and maintenance. Where damp-proofing is being installed as part of a new extension, it's covered under the same building regulations approval as the rest of the extension.
We're a family-run team based in York, and we diagnose damp properly before recommending a fix, rather than reaching for the same treatment regardless of cause. We work on both new extensions and existing York homes across the city and surrounding villages including Haxby, Strensall and Poppleton. Every quote is clear and written, and we're fully insured for the work involved.
Excellent job from Phil and his team. Both external and internal works finished to an excellent quality. Happy to deal with changes and kept us informed on a day-to-day basis. Definitely recommend.
RW Builders directly on 01904 530941, or get in touch through our contact form, and we'll arrange a visit to properly assess the cause. Quotes are free and come with no obligation.