Thetford Roofers carries out commercial roofing installations, repairs and refurbishments for business premises and industrial units in Diss and the surrounding area.
Call any time. Calls are answered day and night and passed straight to our roofers.
Thetford Roofers handles the full range of commercial roofing work: new roof installations on industrial units and business premises, repairs to failing sections, and full refurbishments where a patch-up will no longer serve. We work on both flat and pitched commercial roofs, planning the job around your operating hours to keep disruption to a minimum.
We cover Diss and the towns and villages nearby. Whether your building is a small workshop, a retail unit or a larger industrial facility, the process and the standards expected of the work are the same.
This is the angle most business owners get wrong. A commercial roof rarely fails without warning - but the signs are easy to dismiss until the damage is already expensive. Catching them early is the difference between a repair and a full replacement.
A damp patch or tidemark on a ceiling is rarely where the leak enters the building. Water tracks along joists, decking and membrane layers before it appears inside. By the time you see a stain, the route from entry point to visible damage may be several metres long. A stain that appears after heavy rain, then dries out and returns, is a reliable indicator of an active roof leak rather than a one-off condensation event.
On felt or EPDM rubber flat roofs, blistering happens when moisture gets trapped beneath the membrane and expands in warm weather. Small blisters can be repaired. Large or numerous blisters suggest the membrane has lost adhesion across a significant area and the underlying deck may already be wet. Pressing gently on a blister will tell you whether it contains air (less serious) or liquid (the deck beneath is already damaged).
Flat roofs are designed with a slight fall to move water to outlets. Ponding that persists beyond 48 hours after rain stops means the fall is inadequate, the outlets are blocked, or the roof deck has deflected. Persistent ponding accelerates membrane breakdown and puts extra structural load on the roof.
On industrial units with profiled metal or fibre cement sheet roofs, individual sheets can crack from impact or fatigue. Sheet fixings corrode, allowing sheets to move in wind. A single failed sheet lets water into the overlap with the sheet below, and the water then travels inside rather than shedding at the eaves. One missing fixing can be the cause of a leak that appears metres away from it.
Flashings are the metal or lead detailing that seal the junction between a roof surface and a wall, parapet, skylight or pipe. They are almost always the first part of a commercial roof to fail. Lead flashings crack in frost. Mortar-pointed flashings lose their pointing and admit water. On flat roofs, the upstand - where the membrane turns up the wall - can peel away from the vertical surface if it was not properly bonded or if the adhesive has aged. A failing flashing looks like a minor cosmetic issue but causes the same volume of water ingress as a large tear in the main field of the roof.
Moss holds moisture against the roof surface long after rain has stopped. On pitched roofs this accelerates the breakdown of cement fibre sheets and degrades mortar joints around ridge tiles. On flat roofs, algae and moss retain water at the membrane surface and can eventually force their way into any existing small splits. Removing moss is straightforward when the underlying material is still sound; left until the surface is failing, the removal process itself causes further damage. A commercial building with trees or hedges nearby accumulates moss significantly faster than an exposed industrial site.
Blocked or sagging gutters cause water to back up under the roof edge. On flat roofs this can saturate the timber fascia and the edge of the decking. On pitched roofs it leads to water ingress at the eaves. Gutter joints that have separated will drip constantly onto the wall below, eventually causing damp penetration into the building fabric. Commercial guttering - particularly pressed steel or cast iron on older premises - corrodes from the inside out, so the outside may still look intact while the inside has rusted through.
Most commercial roof failures come down to one of four causes: age, poor original installation, lack of maintenance, or mechanical damage. Age is the honest answer for many flat roofs that have reached 20 to 25 years on a felt system. Poor original installation shows up earlier - typically as widespread adhesion failures on flat roofs or inadequate lap widths on sheet roofs that allow wind-driven rain in. Lack of maintenance allows small issues like blocked outlets or failed sealant to develop into structural problems over several winters. Mechanical damage - from foot traffic during maintenance work, from falling branches, or from poorly anchored plant equipment - creates an immediate breach that then allows moisture to spread laterally beneath the membrane.
Understanding the cause matters before committing to a repair. Patching a roof that has failed due to age across its entire surface is rarely cost-effective beyond the short term.
For commercial flat roof work, the two most practical systems for most premises are built-up felt and EPDM rubber membrane.
These figures assume the existing deck is sound. If the deck needs replacing, that adds to the overall cost and should be priced separately once the existing surface is stripped and the deck condition is assessed.
Ask the roofer whether they will strip back to the deck or overlay the existing membrane. An overlay can be appropriate if the deck is sound and there is only one existing layer, but it hides the deck condition and adds weight. Ask what the drainage falls will be after the job and how they will be achieved. Ask what happens if damaged decking is found once stripping starts - whether that is priced as a contingency or will be quoted separately on the day. These questions tell you whether you are dealing with a roofer who has assessed the job properly.
Not every commercial roof job is a full replacement. Localised repairs - patching a failed section of membrane, reseating a flashing, replacing cracked sheets on a pitched roof - can extend the working life of an otherwise sound roof by several years. The decision between repair and replacement should be based on the age of the roof, how much of the surface area is affected, and whether the deck beneath is dry and structurally sound.
If a flat roof is under 15 years old and the issue is localised to a flashing or a small section of membrane, repair is almost always the right choice. If the same roof is 22 years old and the membrane is showing widespread cracking and loss of mineral surface, a full replacement will be more economical over a five-year horizon.
Commercial gutter repairs are part of what we handle alongside roofing work. On industrial units, gutter runs can be long and the volume of water they carry is significant. A blocked or fractured gutter on a large industrial unit can deposit water directly onto a flat roof edge or against a steel frame, causing far more damage than the gutter repair itself would cost. We also carry out re-cladding work on commercial and industrial buildings where the profiled wall or roof sheeting has reached the end of its serviceable life.
Call us to arrange a roof survey for your commercial premises in or near Diss. We will assess the roof, explain what we find and give you a clear price before any work starts.
No obligation · We'll call you to arrange a free visit
Call any time. Calls are answered day and night and passed straight to our roofers.
