Completed grey single-ply membrane flat roof on a domestic property in Bromley

Flat roofing specialists · Bromley, Kent & London

Single-Ply Roofingin Bromley, Kent& London

A hot-air welded membrane roof that stays watertight for decades, specified for your build-up and installed by a team that fits single-ply every week, not once a year. Free fixed-price quotation, one clean visit to survey, and a 10-year workmanship guarantee behind the finished roof.

Request your free estimate 07753 651460

16 years in flat roofing · Sika, Danosa and Bauder trained · fully insured

16 years specialising in flat roofing

Sika, Danosa and Bauder trained

10-year workmanship guarantee

Fully insured, RAMS for commercial sites

Free fixed-price quotations

Overview

What Single-ply roofing Involves & When You Need It

What it is

Single-ply roofing is a factory-made waterproofing membrane, typically PVC or a similar synthetic sheet, mechanically fixed or adhered to the roof deck and then hot-air welded at every overlap. Because the joints are welded rather than glued or torched, the finished roof behaves as one continuous sheet of waterproofing rather than a collection of separate pieces held together by adhesive. We install Sika, IKO Armourplan, Danosa and Bauder single-ply systems, and the membrane is chosen for the deck, the insulation, the exposure and the way the roof will be used, not for whatever happens to be on the van.

Who it is for

Single-ply suits commercial buildings, warehouses, units, offices, schools and managed properties, and it suits domestic extensions, garages, dormers and flat-roofed additions equally well. It is the right answer for anyone who wants a long-life roof with a clean, flat, modern finish, and for property owners and managing agents who need a system with a documented specification and a guarantee they can hand to a tenant or a buyer.

When it is needed

You need single-ply when an existing felt or asphalt roof has reached the end of its life, when a roof is being rebuilt as part of an extension or refurbishment, when insulation is being upgraded and the whole build-up is coming off anyway, or when repeated patch repairs have stopped holding. If a roof has been repaired more than twice in three years, replacement is almost always the cheaper route over a ten-year window.

Why a specialist matters

Single-ply is only as good as the welding and the detailing. Welds need the right temperature, the right speed and probe-testing afterwards; upstands, outlets, kerbs and terminations need forming properly rather than dressing over. Those are the areas where flat roofs actually leak, and they are the areas a general roofer treats as an afterthought. Platinum Flat Roofing was founded specifically to focus on flat roofing rather than covering every area of roofing, which is why the detailing is the part we spend the most time on.

What happens if it is left

Flat Roof Problems Do Not
Stay the Same Size

Water tracks a long way before you see it

A failed weld or a split at an upstand rarely drips directly below the fault. Water runs along the deck, soaks into insulation and appears metres away, often above a different room. By the time a ceiling stains, the insulation above it has usually been wet for months and no longer performs.

Wet insulation turns a roof job into a building job

Once boards are saturated they lose thermal value, stay damp through winter and start to degrade the deck beneath. A membrane replacement becomes a strip-out, a deck repair and a full re-insulation, and the cost of the work multiplies.

Timber decks rot quietly

Plywood and OSB decks that stay damp lose strength before they show it. Soft spots underfoot, sagging between joists and fixings that no longer hold are the visible stage of a problem that started long before.

Patch repairs stack up and buy nothing

Three or four call-outs and patch repairs across a couple of winters typically cost more than doing the roof once, and none of that spend carries a workmanship guarantee on the roof as a whole.

Common mistakes we are called in to correct

Laying a new membrane straight over a wet or failed build-up because it looks cheaper on the day
Accepting a quote that does not name the membrane system, the insulation or the fixing method
Overlapping and gluing single-ply sheets instead of hot-air welding and testing them
Ignoring falls and outlets, so water ponds on a roof that was never designed to hold it
Choosing on price alone when the two quotes describe completely different build-ups

Our process

Five Steps from First Call
to Guaranteed Roof

01
Inspection

We come out, get on the roof, and look at the deck, the falls, the outlets and the perimeter details. Where a roof has failed we find out why before we price anything.
02
Diagnosis & specification

We confirm the build-up, whether the deck and insulation can stay, and which single-ply system, Sika, IKO Armourplan, Danosa or Bauder, suits the exposure, the fixings and the use. You get a free, fixed-price quotation that names it all.
03
Installation

Strip-out where needed, deck made good, vapour control layer and insulation laid, then the membrane mechanically fixed or adhered and hot-air welded throughout. Upstands, kerbs, outlets and terminations are formed as part of the sheet, not stuck on afterwards.
04
Testing & verification

Welds are probed along their length, outlets are checked for flow, and the finished roof is walked and inspected before we call it done.
05
Completion & guarantee

Site left clean, waste removed, and the roof handed over with a 10-year workmanship guarantee. Manufacturer-backed guarantees are available where applicable depending on the specified system and project.

What you get

The Practical Difference
a Specialist Makes

Welded, not glued

Hot-air welded laps fuse the membrane into one continuous sheet, so the joints are as strong as the material either side of them.

Long service life

A correctly specified and installed single-ply roof is a decades-long asset, not a five-year repair cycle you keep paying for.

Fast, low-disruption installation

No hot works, no torches and no bitumen fumes. On commercial sites that means the building below usually keeps operating while we work.

Light on the structure

Single-ply is light, which makes it a practical re-roof option on decks and extensions that would struggle with the weight of asphalt or a multi-layer built-up system.

Priced before we start

Free, fixed-price quotations as standard. Each roof is quoted individually, no 'from' prices and no figure that moves once the scaffold is up.

Guaranteed workmanship

Every installation carries a 10-year workmanship guarantee, with manufacturer-backed cover available where applicable.

In detail

Single-ply roofing: Materials,
Methods & Variations

Membrane systems we install

We work with Sika, IKO Armourplan, Danosa and Bauder single-ply membranes, and Jamie is Sika, Danosa and Bauder trained with Siltec systems experience. Each manufacturer has its own trims, welding parameters, fixing patterns and detailing components, and mixing components between systems is one of the quickest ways to void a manufacturer guarantee. We install each system as its manufacturer specifies it, using that system's own accessories.

Mechanically fixed, adhered and ballasted options

Mechanically fixed single-ply is fastened through the membrane and insulation into the deck on a calculated fixing pattern, then covered by the next welded sheet. It is fast and well suited to profiled metal and timber decks. Adhered systems bond the membrane fully to the substrate, giving a smooth appearance with no fixing lines, usually preferred on visible roofs and where the deck is concrete. Ballasted and inverted arrangements suit terraces and green roof build-ups. Wind uplift, deck type and exposure decide which is right, and we set that out in the quotation.

Detailing: where flat roofs actually fail

Upstands need to be taken to a proper height and terminated with a compatible trim or sealant bead. Rainwater outlets need purpose-made components welded into the field sheet, not membrane pushed into a hole. Kerbs to rooflights and plant need dressing and welding on all four faces with corners formed correctly. Pipe penetrations need collars. Perimeter drips, verges and wall abutments need the manufacturer's trims. Get those right and a single-ply roof rarely leaks; get them wrong and the membrane in the middle of the roof is irrelevant.

Falls, outlets and standing water

Flat roofs are not flat; they are laid to fall so water reaches an outlet. Where an existing roof ponds, we look at whether tapered insulation can build the fall back in during the re-roof rather than leaving standing water sitting on a new membrane. Outlet size and number are checked against the roof area, and overflow provision is considered so a blocked outlet does not load the deck.

Commercial versus domestic single-ply

On commercial projects we provide RAMS, work around occupied buildings and phase larger roofs so the building stays weathertight overnight. Asbestos awareness training matters on older commercial stock, and photographic reporting can be provided for owners and managing agents. Domestic single-ply work, extensions, garages, dormers and porches, is smaller, but the specification discipline is identical: same systems, same welding standard, same 10-year workmanship guarantee.

Colours, finishes and walk-on areas

Single-ply is available in a range of membrane colours, which matters on roofs overlooked by upper-storey windows. Where the roof will be walked on for plant access, we specify walkway membrane in the traffic route so foot traffic is not wearing the field sheet. Rooflights, balconies and terraces are all detailed into the same welded system rather than treated separately.

Recent work

Single-ply roofing, Completed Projects

Single-ply membrane flat roof with welded seam detailing installed by Platinum Flat Roofing, project photograph 1

Single-ply membrane flat roof with welded seam detailing installed by Platinum Flat Roofing, project photograph 2

Single-ply membrane flat roof with welded seam detailing installed by Platinum Flat Roofing, project photograph 3

Single-ply membrane flat roof with welded seam detailing installed by Platinum Flat Roofing, project photograph 4

Single-ply membrane flat roof with welded seam detailing installed by Platinum Flat Roofing, project photograph 5

Common questions

Single-ply roofing, Your Questions Answered

How much does a single-ply roof cost in Bromley or London?

Every roof is quoted individually; we do not publish 'from' prices because deck condition, insulation, access, roof size and detailing complexity change the figure completely. Quotations are free and fixed price as standard, so once you accept it, that is what you pay.

How long does a single-ply installation take?

A domestic extension or garage roof is usually a short job of a few days; larger commercial roofs are programmed in phases so the building stays weathertight overnight. We confirm the programme with the quotation rather than guessing on the phone.

What guarantee comes with the roof?

A 10-year workmanship guarantee on every installation. Manufacturer-backed guarantees are available where applicable, depending on the specified system and project, and we will confirm in writing what applies to your roof.

How long does single-ply last?

Correctly specified and welded single-ply is a long-life system that should serve for decades rather than years. Service life depends on the system chosen, the exposure and whether outlets are kept clear, which is why we offer planned maintenance.

Can you install over my existing flat roof?

Sometimes, and only when the existing build-up is dry and sound. If the insulation is wet or the deck has failed, overlaying just seals the problem in. We tell you which situation you are in after the inspection.

Do you work on commercial buildings?

Yes: commercial and domestic get equal billing here. RAMS are provided for commercial projects, we are asbestos awareness trained, and we work nationwide on larger commercial schemes from our base in Bromley.

Do you attend emergency leaks on single-ply roofs?

Emergency leak and storm-damage call-outs are accommodated where possible. Call and we will tell you honestly what we can do and when, rather than promising a slot we cannot hold.

Which areas do you cover?

Bromley, Kent, London and the South East, including Orpington, Beckenham, Dartford, Sevenoaks and Croydon, plus nationwide coverage for larger commercial projects.

Is single-ply better than felt?

For most flat roofs, yes. Welded laps remove the weak points found in torch-on overlaps, the membrane is lighter, and there are no hot works on site. The bigger factor is who installs it, the detailing decides the outcome either way.

How do I get started?

Call 07753 651460 or send the enquiry form with your postcode and a short description of the roof. We will arrange an inspection and give you a free, fixed-price quotation with the system named.

Get a Free Fixed-Price Quote
for Single-ply roofing

Tell us about the roof and your postcode. We will inspect it, tell you what has actually failed and give you a fixed price, backed by a 10-year workmanship guarantee.