Rooflight Condition Inspection Report

Report: Condition of rooflight and surrounding ceiling

44 Patrick Street, Peel, Isle of Man for Mrs L Machado-Williams

Location

The rooflight is on the east-facing roadside pitch of the slated roof of this terraced house in Patrick Street, providing supplementary lighting to the attic bedroom. It is faced across the road by the thick stand of trees behind the boundary wall of Heathfield House, 1, 2.

1, above: No. 44 Patrick Street is the house with cream render on the right. The trees on the left are in the grounds of Heathfield House.

2, right: It is difficult to gain sufficient elevation to view the rooflight from the road, or to evaluate the effectiveness of the flashings. {{image:193771}}

Inspection, 9th February 2017

The rooflight is similar to the typical Velux, but by a different manufacturer (not identified), and with a different style of flashing which covers the upper half of the window externally, above the centre pivot point. This flashing is unlikely to provide complete protection from driving rain when at this pitch and under the degree of severe exposure experienced in the Isle of Man.

The inspection revealed a significant amount of staining to the sloping ceiling to the sides of the window and below it. This appeared to have been caused by a mix of condensation run-off and penetration by driving rain. Driving rain would be occasioned by the severe exposure making the window vulnerable when subjected to winds from the east, north-east or south-east during periods of heavy rain, 3, exacerbated by failure of the seals.

At the time of inspection, there was negligible dampness to the surface finish of the ceiling, and the only significant damp in the frame to the window was found in one piece of timber within the composite window frame adjoining the pivot hinge on the south side, 4. It is clear, however, that from time to time, more of the timber-work has been damp, 5, 6.

The seals consist of a thin adhesive strip that had become displaced on the north side of the window. This was repositioned temporarily, but needs replacing. It is apparent that the trees across the road exude a considerable amount of sticky reside and litter from the flowers and that this has built up within the seals to the rooflight, compromising performance. To combat this, the rooflight needs more regular maintenance than has been carried out to date, 5, and the seals need regular maintenance and replacement.

Recommendations

This window needs regular maintenance, more than would be normally necessary. This should involve both periodic cleaning to remove litter and residue and replacement of the seals by a certified window fitter, who should also check the condition of the window for damp penetration. The wet section of timber (see 4) needs to be cut out and replaced, if this is feasible. If not feasible, then when taking into consideration the other evidence of decay in the timber, the option of replacing the window should be considered, either by a fixed light or a top-hung rooflight. The latter would avoid the problem currently occurring in the vicinity of the pivot hinge.

Compliance with Building Regulations (both opening lights to offer minimum ventilation of 1/20th floor area of habitable room, measured over space with ceiling height greater than 1500 mm) may need to be negotiated with the Building Control Officer.

Patricia A Tutt, 2 March 2017

Patricia A Tutt, Dip Arch, RIBA, Cert Ed, ARPS, PhD 3 Patrick Street Peel Isle of Man IM5 1BP British Isles

3, above: general view of the window from the attic room.

4, above: the inset piece of dark timber records as being very wet when tested with a moisture meter. The remaining timber was only negligibly damp on the day of inspection (2.2.17).

5, above: litter and sticky residue from the trees has accumulated in the hinge, under the cover flashing, and along the seals.

6, above: the lower left-hand corner, seen from the attic. Staining is evident in the corner of the frame and the timber surround. Persistent dampness has caused some decay in the frame, although this was relatively dry at the time of inspection.