Damp Proofing & the benefit of added insulation
DAMP PROOFING & THE BENEFIT OF ADDED INSULATION
Damp Proofing Problems
No vertical damp proof was course in place at the ajoining wall from old to new part of the property where a solid wall meets the extension cavity wall.
No insulation was present in the cavity wall structure causing cold spots
The old fireplace had been boarded over without ventilation causing condensation.
Remedy..
A damp proof course was added to reduce the incidence of moisture rising in the existing wall creating damp and cold spots. This technique involves injections of damp proof course cream both horizontally and vertically. This stops moisture rising and bridging. A damp proof membrane was then fixed to both walls using plaster plugs, reinforced with battens and secured with brick plugs. The membrane was then fixed in place below the finish floor slab and sealed. Positioning the membrane this way, blocks out any residual dampness, salts and sulphates that are liable to be present in the fire place and chimney breast.
A vent was installed to encourage air circulation within the existing chimney and a membrane was fixed to the wall with plaster plugs. The membrane was over battened with 50mm x 38mm battens secured with brick plugs. The battens were then infilled with a 2mm insulation board. The insulation backed plaster board was then fitted to the battens over the insulation infill to prevent thermal bridging, creating a flat wall ready to receive two coats of plaster finish.
In conclusion..
A damp proof membrane will prevent moisture and salts from penetrating the new plaster work, but it is important to also include the injection technique when dealing with damp problems. The insertion of injectable creams inhibit rising damp behind membranes, reducing the incidence of cold spots and moisture within the masonary. Adding insulation keeps the walls warmer which prevents the finished plaster work from exposure to cold temperature and reduces condensation forming. This is especially useful in high moisture areas such as bathrooms with solid 9 inch walls, where warm air containing high levels of moisture settle on cold walls causing condensation.
For all your damp proofing solutions contact the experts at Wye Valley Heritage in the first instance.
