Existing Basement Waterproofing

Historic or modern basements can often exhibit dampness, or seepage, due to defective or missing waterproof systems; manifesting as tidemarks on damp masonry or plaster, or even free flowing water. Older, historic buildings generally wouldn't have had a basement waterproof system installed, whereas more recent builds would generally have a tanking or waterproof membrane system installed, which has since failed.

At Stronghold Preservation, we would carry out a survey to assess the basement, and make proposals as to the most preferable solution to achieve a dry basement. We provide a 10 year insurance backed guarantee for all basement waterproofing where we have provided the design detail, and installed the basement waterproofing system.

When deciding on the best option to waterproof an existing basement, the options can be put into three categories:

-          A barrier system, which will hold back the water

-          A cavity drain system which will manage and expel any water ingress

-          Leak sealing repair system; used generally in waterproof concrete constructions.

Waterproof Barrier Systems

Traditional 'Tanking' would fall into this category.  A waterproof internal (or external, if existing) membrane is bonded to the basement structure to prevent water ingress into the internal environment; eg bonded sheet membranes, cementitious tanking, bentonite matting.  To be completely successful in providing a dry basement, the workmanship needs to be defect free, which, according to BS8102, is very difficult to achieve, especially where the work has been carried out by non-waterproofing specialists.  If the barrier is compromised (for example, punctured by a nail or tears due to movement in the retaining wall), then the barrier becomes ineffective at holding back the water, causing a damp basement.  Our experienced surveyors will assess your basement and design the most suitable system for your basement, to meet your specific needs.  The existing basement may already have a barrier type waterproofing system, either internally, or externally, which may have failed, resulting in the damp.

Cavity Drain Basement Waterproofing System

Cavity drain systems manage any water which may penetrate through the retaining wall, diverting the water away from the internal environment.  A drain is installed internally at the base of the existing basement retaining wall, and a membrane fixed to the existing walls.  Any water passing through the retaining wall drips into the drain, before being moved, by pump or gravity, into the existing storm drainage.  The floor also needs to have a waterproof membrane.  This system is suitable for use in concrete or masonry basement walls; existing or new build.

Leak Sealing Repair System

Stronghold Preservation also use an innovative leak sealing system for dealing with damp in existing basements; though it may not be suitable for all basement damp problems.  Therefore it is imperative that one of our knowledgeable surveyors assess the basement to advise on the most suitable solution.  Leak sealing uses a resin, which is pumped into the retaining wall via pre-drilled holes, until the leak is sealed; our trained technicians can instantly recongise when the leak has been effectively sealed.  This leak sealing system is often used in underground car parks, lift pits and underground plant rooms.

Stronghold also provide a service duct sealing service, to prevent water ingress through the ducts.