Frequently Asked Questions

In pre-1900 properties, there was often no original damp proof course (DPC) installed at all. In properties built between 1900 and 1970, original slate or bitumen felt DPCs typically degrade after 25-50 years due to settlement and ground movement. Additionally, raised garden beds, driveways, or internal plaster bridging can bypass the original damp course.

Rising damp originates exclusively from the ground and is drawn up by capillary action, stopping around 1 to 1.5 metres high. Penetrating damp occurs when external rainwater penetrates directly through building defects at any height, such as cracked masonry, porous brickwork, defective render, leaking gutters, missing roof tiles, or compromised window seals.

A DPC is a continuous impermeable barrier across a wall that prevents moisture rising from the ground. In existing properties where the DPC has failed, we inject high-grade silane-siloxane cream into the mortar course. The active silane diffuses through the masonry capillaries, reacting with silica to form a permanent water-repellent silicone barrier that stops rising damp while letting the wall breathe.

Damp proof injection creams are designed to penetrate deep into masonry. The active ingredient, silane, lines the pores of the brick or stone and cures to form a long-lasting water-repellent barrier. Unlike physical membranes, this method creates an invisible defence against rising damp while allowing the wall to breathe. Depending on the property, injections can be applied using low- or high-pressure techniques. As damp proofing specialists, we recommend the most effective method for each property to ensure permanent results.

Penetrating damp occurs when external defects allow water to soak through walls. Common causes include cracked masonry, porous brickwork, defective render, leaking gutters, missing roof tiles, or poorly sealed window and door frames. Ground levels higher than internal floors can also lead to damp ingress, especially in basements and cellars. Left untreated, penetrating damp can damage plaster, timber, and internal finishes. Our penetrating damp treatment stops water penetration, restores your walls, and ensures long-term protection with professional waterproofing solutions.

Spotting rising damp early prevents serious property damage. Key signs include tide marks, yellow or brown stains along skirting boards, and salt deposits on plaster. As moisture rises through the walls by capillary action, salts are left behind, often creating a damp smell, fluffy white deposits, or crumbling plaster. Black mould at skirting board level can also indicate rising damp, while peeling wallpaper and bubbling paint are common warnings. If you suspect rising damp, our damp proofing specialists can provide a free survey and tailored damp treatment to protect your home.

In older properties, there may be no original damp proof course (DPC) at all, which leaves walls unprotected against moisture from the ground. Even where a DPC exists, many early systems made from slate or bitumen felt only last 20 to 25 years before breaking down. Once the DPC fails, moisture travels upwards through mortar and brickwork, causing internal damp patches, blown plaster, bubbling paint and salt eruptions. If left untreated, rising damp can spread further and lead to structural issues, so timely DPC installation or remedial treatment is essential.

Condensation is caused by airborne humidity cooling against cold external wall surfaces, typically forming black spot mould (Aspergillus / Stachybotrys) in room corners, behind wardrobes, and around cold window reveals. Rising damp, on the other hand, carries hygroscopic subsoil mineral salts (nitrates and chlorides) which prevent mould but cause crystalline efflorescence, tide marks below 1.2m, and decaying timber skirtings. We use electronic electrical resistance meters and carbide bomb testing to diagnose the true root cause.

Traditional cementitious tanking (Type A) acts as a physical barrier trying to withstand hydrostatic groundwater pressure. If water pressure builds or the substrate develops micro-cracks, leaks can occur. Type C Cavity Drainage uses a high-density studded membrane to depressurise water ingress, directing it silently through perimeter AquaChannels to a dual sump pump station that discharges it safely away.

Our professional basement sump pump installations include dual submersible pumps (primary + secondary backup) and can be fitted with an uninterruptible battery backup inverter and acoustic high-water alarm. If mains electricity fails during a storm, the battery inverter automatically kicks in to maintain continuous pumping.

Dry Rot (Serpula lacrymans) produces deep cubical cracked brown timber, white cotton-wool mycelium, and mushroom-like fruiting bodies with rusty spore dust. Critically, dry rot strands can travel through brickwork and plaster to attack dry timbers across the building. Wet Rot (Coniophora puteana) is darker, soft/spongy, and strictly confined to areas with continuous moisture (over 40-50% wood moisture content).

We treat infested roof rafters, floor joists, and floorboards using HSE-approved water-based permethrin micro-emulsion sprays. The insecticide penetrates deep into the wood fibres, eliminating active wood-boring larvae and creating an enduring protective barrier that kills emerging adult beetles, breaking the reproductive lifecycle. Safe re-entry is achieved in just 1 to 2 hours.

Yes, we provide free initial visual damp inspections and itemised, transparent quotations for homeowners looking to resolve damp, condensation, or timber issues in their properties across Berkshire, Surrey, and surrounding towns. (Specialist written pre-purchase mortgage diagnostic reports are available with rapid turnaround).

We typically arrange priority on-site diagnostic surveys within 24 to 48 hours across Reading, Bracknell, Wokingham, Guildford, Slough, Windsor, Henley, and surrounding areas. For urgent pre-purchase surveys or severe water ingress, same-day and next-day inspection slots are often available by calling 01784 918841.