On this project we applied a roof to a newly built extension and made vital repairs to the existing roof. The house extension was constructed to the same dimensions as the existing house. The original farmhouse has a stone slate pitched roof. The stone extension was constructed to the same roof-line as the existing farmhouse. The farmhouse roof had been re-roofed around 15 years ago but was to a very poor quality.
Once all the steel beams & rafters were installed on the new extension, our team striped back the roof on the original section of house. A weight bearing scaffold was erected so the stone slates could be kept at roof level and provide access for our roofing team.
Once the slates had been removed we lifted the old timber battens & roof felt. The roof had a bitumen based under felt, this always tends to go brittle and crack. The bitumen felt is also none breathable. This was replaced with a new modern roof liner.
When the previous roofing contractor installed new timber rafters they were left short on the ridge beam. We decided to extend the roof rafters by planting new timber work to the side of the existing. The existing timber rafters were in good conditions with no signs of rot. We used a treated C16 timber for the new rafter extensions, bolted with M12 coach bolts. Then the new rafter extensions were screwed to the oak ridge beam. Some of the rafters also required extending on to the wall top, we use the same technique.
90% of the rafters needed to be extended to sit right on the ridge beam. The original oak perlins & ridge beams were also in good condition, they had a high moisture content around the chimney area where the flashing had failed.
While the stone roofing slates had been striped we also removed all the loft insulation. The attic area was then vacuumed out to remove excess dust & debris. We then relay loft insulation to depth of 300mm. At this stage we treated the roof timbers for Dry-rot, Wet-rot & Woodworm, with a liquid spray.
For this stone slate roof we had to import 14 tons of new stone slates. We used aluminium pegs to hold the stone slates in place. These pegs make it easier to change broken slates at a later date.
The old stone flashing’s around the chimney was also removed & we installed new lead aprons & flashing.