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Slate Roofing & Dormer Cladding Manchester

Slate Roofing and Dormer Cladding

This example illustrates the refurbishment of all the roof systems on a domestic house in Manchester.

The various roof elements had multiple issues and it made economic sense to modernise the entire roof system rather than undertake repairs to the individual elements.

The existing slate roof had damaged slates and ridge tiles and lacked the waterproof breathable membrane expected today. The decayed/rotten timber fascia and soffits and needed replacing.

The roof dormer showed signs of stress and potential problems with the deck, felt roof covering and the lead cladding on the sides.

The bay window roof similarly showed signs of its age and the materials had reached the end of their predictable lifes

Repairs and Replacements

• We erected scaffolding for roof access
• The existing roofing materials were stripped off and wither dispose of if damaged or stored ready for reuse and installation:
  • slates
  • wooden battons
  • lead flashings and valleys
  • ridge tiles
  • Velux windows

• Reclaimed Welsh slates were acquired and installed over the entire roof area. This ensured a uniform roof with minimum variation in the colour/shade, grade, thickness and steps of slate.
• A waterproof breathable membrane, a secondary protection system, was positioned over the structural timbers and fixed. The membrane seals the roof against wind blown spray that could enter under the slates
• The membrane is mechanically fixed to the structural roofing timbers under 25x50mm wooden battons, positioned horizontally and onto which the slates are fixed.
• The battons are set at specific intervals for the courses of reclaimed Welsh slate
• Slates are raised onto the scaffold and fixed to the battons so the smaller slates are positioned towards the top of the roof. This minimises the roof loading
• Code 4 lead (a British Standards quality classification) is installed for chimney flashings, aprons and roof valleys

Velux Windows

• The existing skylight windows were unsound and were replaced
• Replacement Velux windows were installed using new flashings to ensure a watertight finish

Ridge Tiles

• High grade ridge tiles are mechanically fixed along the ridge. The specific tile is designed for locations at risk of high wind speed and turbulence
• The Redland Smooth Uni-Angle dry fix system is installed on all hips and ridges
• Roof slates are cut to suit the roof hip
• An adhesive membrane forms a seal under the tiles and ads structural integrity to the ridge
• The dry fix ridges are positioned and mechanically fixed to the hip rafter

Timberwork

• We installed replacement timber fascias for the hip apex

Dormer Lead Cladding

• All existing defective (i.e. variable thickness, evidence of thermal movement) lead cladding was stripped from the dormer and removed from site
• New Code 5 lead was installed to clad and seal the dormer cheeks
• Installation techniques are to LDA regulations for cladding, welt joints and flashings. This ensures long life, weather proof seal and minimal thermal movement

Dormer Flat Roof

• The flat dormer roof was in a poor state of repair and required a replacement deck and recovering. We removed the existing defective felts, decking and timber fascias
• Firring pieces (3" down to 0") were installed and fixed to provide the falls on the roof that would improve drainage
• We replacemd the timber deck with 18mm WBP (Weather and Boil Proof) plywood decking. The internal dormer was not affected
• 50mm x 50mm tilt fillets (3 edged raised upstands) were installed - these channel the water towards the front guttering
• For a long life, we installed a built up felt 2 layer torch on flet system. The specification suites the roof type and usage, local environmental factors and lifetime requirements, and the cost that best suited the purpose
• Green mineral felt drips were supplied and installed to the perimeter
• New guttering and rainwater goods/guttering and down pipes with seamless aluminium profile were installed
• uPVC fascias were installed for long life and easy maintenance.