How No-Fines Concrete Construction Works
No-fines concrete is produced by mixing coarse aggregate with cement and water, deliberately excluding the fine aggregate (sand) that would normally fill the voids between the larger particles. The result is a porous, open-textured material that offers good thermal insulation properties relative to dense concrete, but which differs structurally from standard reinforced concrete. Wimpey built houses using this material as in-situ poured construction, pouring the concrete into moulds formed around the structural openings and allowing it to cure in place.
The resulting structure is monolithic — the walls, floors, and roof connections form a single continuous concrete mass — which gives Wimpey No-Fines houses good structural rigidity but also means that any defects or deterioration in the concrete are difficult to remedy without significant structural intervention. The most common concern for surveyors is carbonation of the concrete and its potential effect on any embedded steel reinforcement, as well as the condition of the external render that protects the porous concrete from moisture penetration.
Because no-fines concrete is not a PRC (Precast Reinforced Concrete) type, the PRC certification scheme does not apply to these properties. There is no equivalent approved repair scheme with associated certification. Lender decisions on Wimpey No-Fines houses therefore rely primarily on the outcome of a specialist structural survey rather than on any certificate or warranty.
Which Lenders Will Consider Wimpey No-Fines?
Because Wimpey No-Fines was not designated under the Housing Defects Act 1984, it occupies a different position in lender criteria from fully designated PRC types. A number of building societies and some specialist lenders will consider Wimpey No-Fines properties subject to a satisfactory structural survey. This is in contrast to designated types such as Airey or Cornish Unit, where a PRC certificate is the primary threshold requirement.
Lenders who will consider Wimpey No-Fines typically require a full structural survey (RICS Level 3) from a surveyor with experience in concrete and no-fines construction. The survey must confirm that the structure is sound, that there is no significant carbonation affecting embedded steel, and that the external render is in good condition and providing adequate weather protection. Where the render has failed or the concrete shows signs of deterioration, the lender may require repairs to be carried out before proceeding.
Loan-to-value limits for Wimpey No-Fines are typically lower than for standard construction — most lenders willing to consider them will cap at 75-80% of surveyed value. Rates may be slightly higher than standard products but are often reasonable with the right lender. A specialist broker is essential to identify the currently active lenders and their precise requirements.
