North Walsham Roofers carries out flat roofing work on extensions, garages and outbuildings in Sheringham, and this page walks you through exactly what a proper job looks like from first visit to final clear-up.
Homeowners who know what a flat roofing job involves are in a much better position when it comes to getting quotes, asking the right questions and spotting whether a roofer is cutting corners. A flat roof done quickly and cheaply often fails quickly. A proper installation takes time and follows a clear sequence of steps - none of which should be skipped.
Below is a straightforward account of how a flat roofing replacement or new installation should proceed, from the first look at your property through to the finished job.
Before any price is given, the roof needs to be inspected properly. That means getting up onto the surface, not just looking from ground level or a ladder top.
A thorough survey covers the following:
The outcome of the survey determines exactly what the job involves. A roofer who quotes without getting up and checking the deck is guessing, and that guess can leave you with a bill for additional work once the old surface is stripped.
On a replacement job, the existing material comes off first. Old felt, any loose or deteriorated chippings and any failed insulation are stripped back to the deck. This is the point where the true condition of the deck becomes clear.
If the deck is plywood or OSB and sections of it are soft, spongy or delaminated, those sections need to come out and be replaced before anything else happens. Laying a new membrane over a compromised deck is one of the most common shortcuts that causes expensive problems later. The replacement boards should be fixed securely to the joists below, not just to the surrounding deck.
All stripped material is loaded off the roof and disposed of properly. The area should be left ready for the next stage, with no loose debris on the surface or around the property.
Once the deck is stripped and any necessary board replacements are complete, the surface is inspected again and any remaining fixings or sharp edges are dealt with. On timber decks a layer of insulation board is often added at this stage - particularly on extension roofs where keeping heat in matters. The insulation is laid flat, joints staggered to avoid cold bridges, and either mechanically fixed or bonded depending on the system being installed.
The deck preparation also includes fitting or checking any upstand timbers at the roof edges and against walls. These form the basis for the upstands of the membrane, which is where the roof edge is made weathertight.
The choice of membrane - EPDM rubber or mineral felt - determines the installation method, but both follow the same basic principle: the membrane must be fully bonded, lapped correctly and turned up at every upstand.
EPDM rubber: The membrane arrives as large rolls and is cut to size on site. The deck is primed first, then a contact adhesive is applied to both the deck and the underside of the membrane. Once the adhesive reaches the correct tack, the membrane is rolled out and pressed firmly into place. Seams and laps are made with specialist tape designed for EPDM, which bonds mechanically to the rubber. The edges are turned up against the upstand timbers, folded neatly at corners and bonded fully. On a garage-sized roof this stage typically takes most of a working day for an experienced team.
Mineral felt: Three-layer torch-on felt is applied using a gas torch to heat the underside of each sheet, bonding it to the layer below. Each layer is lapped over the previous one according to the manufacturer's specification - usually a minimum of 75mm side laps and 150mm end laps. The top layer carries a mineral finish that reflects UV and provides the wearing surface. Felt work requires careful handling of the torch near timber, and the deck should be dampened if dry to reduce fire risk during application.
The membrane alone does not make a roof watertight at every point. Where the roof meets a wall, a lead or code-lead flashing is dressed over the upstand and cut into the mortar joint above. This is done in sections, overlapping, and pointed with fresh mortar or sealant. The flashing must follow the line of the wall and lie flat against it - a flashing that stands proud will catch water and allow it to track behind.
Drip edges and fascia trims are fitted at the roof perimeter to direct water into the gutter cleanly and prevent it tracking back under the edge of the membrane. Outlets are checked, cleared and refitted or replaced if they have degraded.
Once the membrane and all flashings are in place, the completed roof should be inspected before anyone packs up. All laps are checked by hand to confirm full adhesion. Upstand corners are inspected for splits or un-bonded areas. The fall to the outlet is confirmed visually - if there is any doubt, a jug of water poured at the highest point should run cleanly to the outlet without pooling.
Any area that does not pass this check is remedied on the day, not left for later.
All off-cuts, packaging, old felt and stripped decking are removed from site. The gutter is checked and cleared if it caught debris during the strip. The surrounding area - including any paths, garden or driveway below the working area - is left as it was found.
A good roofer does not leave the customer to deal with the mess. Ask any contractor you speak to what their site-clearance practice is before work starts.
We carry out flat roofing work in Sheringham and across the surrounding area of North Norfolk. If your property is in North Norfolk, call us to confirm we cover your area.
If you want to understand exactly what your flat roof needs and what the job will involve, call North Walsham Roofers to arrange an on-site survey in Sheringham. We will walk you through what we find and what we propose to do about it before any work begins.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
