Poorly ventilated loft space leads to rot

A recent Homebuyer Report conducted on a semi-detached house revealed extensive dry rot in the rafters. The loft access hatch was located over the en-suite shower room and the timber hatch was very small and access limited. However, the surveyor managed to enter the void to carry out a full inspection.

The roof insulation was noted to be approximately 150mm in thickness, and there was excessive debris, carpet rolls, cardboard boxes and other items which required clearing out. (Currently it is normal to upgrade the thickness of the insulation within the roof, to a minimum of 270 mm thick. Grants from Local Authorities to accomplish this may be obtained.)

The underside of the roof covering had been under-laid with felt, but some of the carpet stored in the loft space, as well as the insulation itself, was excessively damp. Furthermore, rainwater staining was clearly visible on the timber rafters suggesting extensive leaks in the roof.

More worrying, however, was the discovery that the insulated roof void was not suitably ventilated. This was identified by the surveyor as the likely cause of the excessive condensation, which, due to the signs of deterioration, had been present for a significant period of time. The condensation had lead to rot in the roof timbers. Poor ventilation of roof spaces was a common problem in buildings of this age, but as the current arrangements were unsatisfactory, ventilation needed be immediately improved.

The improvements would hopefully arrest the spread of rot, allowing a detailed assessment of the existing damage to be made. The installation of eaves vents, to ensure adequate roof void ventilation and prevent future rot to the roof timbers, was suggested by the surveyor. Given the relatively low cost of this compared to wholesale roof repairs, the seller was happy to arrange for this to be carried out prior to exchange of contracts, lest the buyers decide to pull out.

Post Author: Frances Traynor