Roofing Cambridge - Pitched to Flat Roof Conversion - Roofing Cambridge

Roofing Cambridge – Pitched to Flat Roof Conversion

Project Facts

Project Detail

Roofing Cambridge –

OBSERVATIONS:

There are two adjoining sections of roof on the property that were inspected. A garage flat roof which intersects with a mono-pitch ‘lean-to’ roof that covers the porch area.
The garage roof comprises a bituminous mineral felt with pre-fabricated steel joists and ‘stramit’ boards form the substrate. The roof had clearly reached the end of its lifespan with numerous splits and cracks noted along the perimeter which were visible from ground level.
The lean-to structure over the porch roof is clad in concrete pantiles. The exact product was not identified. The roof has been built at a pitch angle of between 11 and 3.7 degrees. The lowest conceivable ‘recommended’ pitch for tiles of this profile is 15 degrees. The consequence of this is ongoing water ingress entering the roof space by a process known as ‘capillary action’.

RECOMMENDATIONS:

To replace the existing garage roof with a new membrane. Due to the construction of the substrate and supporting structure, new supporting timbers will need to be installed along with new timber decking to support the new membrane.
To remove the existing tiles, batten and felt of the porch roof and install a ‘singleply’ membrane that is appropriate for the gradient of the roof slope.

DESCRIPTION OF WORKS:

1. Garage: To supply and install new 1.52mm EPDM single ply membrane:

• Manufacturer: Firestone.
• Material: EPDM.
• Thickness: 1.52mm.
• Colour: Charcoal.
• Perimeter: uPVC
• Warranty: 25 years.

To supply and install new timber decking.

• Decking thickness: 18mm Oriented Strand Board timber

2. To supply and install new supporting timber carcassing.

3a. Fascias – To supply and install new white uPVC fascia boards.

• Manufacturer: Eurocell
• Material: uPVC
• Colour: White
• Depth: 200mm
• Profile: L-Shape
• Product/Workmanship Warranty: 10 years.

3b. Guttering – To supply and install new half-round guttering & downpipes to garage and front main roof:

• Manufacturer: Eurocell

• Material: uPVC
• Colour: Black
• Profile: Half-round.
• Warranty: 10 years.

4. Porch: To supply and install new 1.52mm EPDM single ply membrane:

• Manufacturer: Firestone.
• Material: EPDM.
• Thickness: 1.52mm.
• Colour: Charcoal.
• Perimeter: uPVC
• Warranty: 25 years.

To supply and install new timber decking.

• Decking thickness: 18mm Oriented Strand Board timber

5.  – To supply and install 1no. polycarbonate dome skylight:

• Manufacturer: Rooflights and Glazing Ltd
• Dimensions: 900mm x 900mm
• Opening Mechanism: Fixed.
• Thickness: Double skin
• U-Value: 2.9Wm2K (guidance)
• Upstands: Bespoke timber construction.
• Warranty: 10 years.

Built Process