Flat Roofing in Godalming

Wey Valley Roofing is rated 5.0 out of 5 from 9 Google reviews, displayed through Trustindex, and the work behind that is flat roof build-ups laid to a proper fall with the detailing done once.

Scott has spent more than 36 years on Surrey roofs and still answers the phone himself, whatever the hour, whether you need a flat roof upgrade or a roofer in Godalming for something smaller.

Call 07428 300474 for a free survey and an honest fixed price in writing.

The three types of flat roof most people mean are warm roofs, cold roofs and inverted roofs, and the covering over them is usually EPDM rubber, GRP fibreglass or torch-on felt. Which one suits your building depends on the deck, the insulation depth available and how the water gets off.

Flat Roofing Systems

A flat roof is not flat. It is laid to a fall, and BS 6229 sets the design out so that water reaches the outlet rather than sitting in a hollow. A minimum finished fall of 1:80 is the usual working figure, which means firring pieces on a timber deck cut to taper across the span, or tapered insulation where the deck itself cannot be altered. Ponding is the single most common reason a flat roof fails early, and it is nearly always a fall problem rather than a membrane problem.

The system is the whole build-up, not the top sheet. On a timber deck that means joists at their existing centres, an 18mm OSB3 or WBP plywood deck, a vapour control layer, the insulation, then the waterproofing. Get the order wrong and you build a condensation trap.

• Warm roof: insulation above the deck, vapour control layer below it, no ventilation void required. This is what we fit on almost every domestic upgrade.
• Cold roof: insulation between the joists with a ventilated void above it, needing a clear 50mm airway and cross ventilation at the eaves.
• Inverted roof: insulation laid over the waterproofing, ballasted or paved, used on terraces and decks that take foot traffic.

Ventilation and condensation are handled under BS 5250, and rainwater outlet and gutter sizing under BS EN 12056, so the outlets are chosen for the roof area they actually serve rather than whatever fitted the old hole.

Flat Roof Waterproofing and Insulation

Waterproofing performance comes from the detailing at the edges, not the middle of the field. Upstands are taken a minimum of 150mm above the finished surface, terminated under a lead flashing or a proper termination bar, and outlets are dressed into the membrane rather than sealed with mastic afterwards. Where a flat roof abuts a wall, the leadwork follows Lead Sheet Association guidance for code and fixing centres, because a flashing that expands and cracks will leak long before the membrane does.

Insulation depth is set by the U-value you need to hit. On a replacement covering that counts as a renovation of a thermal element, the target is 0.18 W/m²K, which in practice means roughly 120mm to 150mm of PIR board depending on the product. Approved Document L's 25% rule sits alongside this on larger re-roofs, and we explain where it applies at survey rather than raising it once the scaffold is up. Whether you need flat roofing in Godalming or flat roofing services Guildford, the same standards and the same written guarantee apply.

• Vapour control layer: laid continuously under the insulation and lapped and sealed at every joint, including up the upstands.
• PIR insulation: boards staggered and butted tight, cut around outlets and pipe penetrations rather than packed with offcuts.
• Tapered scheme: used where the existing deck has no fall and raising the whole roof would foul a door threshold or a window cill.

Flat Roofing Materials for Godalming Homes

Godalming holds Georgian, Victorian and Edwardian stock alongside estates built between 1950 and 1980 in Binscombe, South Hill, Farncombe Hill and Twycross, Bargate Wood and Aarons Hill. Those later estates brought a lot of flat roof detailing with them: garage roofs, rear extensions, dormer cheeks and porch canopies. The material choice follows the deck and the exposure rather than a preference.

• EPDM rubber: a single sheet, typically 1.2mm or 1.5mm, bonded down and cut to fit with no seams across the field on most domestic roofs. Suits garage and extension roofs well.
• GRP fibreglass: resin and matting laminated in place over an OSB3 deck, with preformed trims at the edges. Gives a hard, walkable finish, and it wants a dry spell and a sound deck to cure properly.
• Felt, torch-on or built-up: two or three layers, a torched underlay and a mineral cap sheet. Still the sensible answer on complex roofs with plenty of penetrations and awkward abutments.

Riverside properties along the River Wey and the towpath towards Farncombe sit low, and low-lying ground shows up in how much standing water and leaf litter a roof deals with. On those we pay closer attention to outlet sizing and to keeping the fall generous.

Flat Roof Repairs

A repair is worth doing when the deck underneath is still sound. We check that first by lifting a section rather than guessing from below, because a damp patch on a ceiling can be two metres from where the water actually enters. Split laps, blistered felt, a failed outlet collar and a cracked upstand flashing are all repairable. Soft, spongy decking and water trapped in the insulation are not, and we will say so.

Where the covering has one localised failure and thirty years of otherwise even wear, a patch is honest work and we quote it as a patch. If a smaller repair will do the job, that is what goes in the written price rather than a replacement roof.

Flat Roof Replacement for Godalming Homes

Replacement is staged so the building stays usable. Most of the noise on a flat roof job is the strip out and the fixing of the new deck, and both happen from above. The room below stays in use for the majority of the work, and nothing comes through the ceiling.

1. Survey and written price

Scott looks at the roof properly, including a drone view where a parapet or a height makes it sensible, then puts a fixed price in writing with the build-up specified. No charge and no obligation.

2. Strip out and deck

Old covering and wet insulation come off to the joists and go straight into a skip or bagged off the roof. Rotten deck boards and any failed joist ends are replaced, and the new deck is fixed at the correct centres.

3. Vapour barrier, insulation, membrane

Vapour control layer, then insulation, then the chosen covering with all upstands and outlets dressed in. This is the quiet part of the job. Weather is watched daily and the roof is left temporarily waterproof at the end of every day it is open.

4. Trims, rainwater and handover

Edge trims, drips, outlets and any leadwork finished, gutters cleared and tested with water, site swept, and the 25-year written workmanship guarantee handed over before the team leaves.

Access is agreed before anything arrives. Skips and materials are placed where they do not block a shared drive, and in the tighter period streets near the centre we plan the drop and the loading rather than turn up and take the road.

Flat Roof Installation

New installation on an extension or a garage starts with the structure. Joist span and depth, deck thickness and fixing all follow the load, and fixings and wind uplift are worked to BS 5534 where the roof interfaces with tiling or edge details. Perimeter fixings are closer together than field fixings because that is where uplift bites hardest.

Asbestos-cement garage roofs are common on the post-war estates. Where one turns up we assess it and advise the safe, compliant route under the Control of Asbestos Regulations 2012. We do not carry out licensed removal ourselves, and we will tell you plainly what is needed.

The same team covers flat roofing services.

Commercial and Domestic Flat Roofing

The build-up logic is the same on a shop roof as on a rear extension: fall, vapour control, insulation, membrane, outlets sized to the area. Commercial roofs simply bring bigger areas, more plant penetrations and more outlets, and they usually need the work phased so the building keeps trading. Our flat roofing services cover both, with the same standards written into the quote.

Work is carried out by our own roofers, never subcontracted out, and the business is fully insured with Public Liability Insurance. Scott has spent more than 36 years on Surrey roofs, and a real person answers the phone day, night and weekend.

• Domestic: extensions, dormers, porches, bay roofs, garages and balcony decks.
• Commercial: larger membrane areas, plant and pipe penetrations, phased access and out-of-hours working where needed.
• Both: honest fixed price in writing, tidy site, and the guarantee in your hand at the end.

Common Questions About Flat Roofing in Godalming