The finished garden bar roof — EPDM complete, Bolton, Lancashire
This is the finished result — a solid, weathertight garden bar roof in Bolton, Lancashire, built from scratch on an existing blockwork structure. The EPDM rubber membrane is fully bonded across the entire roof, the timber fascia boards are fitted neatly around the perimeter, and the whole build-up — joists, OSB 18 decking, vapour barrier, rigid insulation, and EPDM — is performing exactly as it should. The customer now has a proper, permanent garden bar they can fit out and enjoy all year round. Here's how we got there, step by step.
Side elevation — EPDM rubber roof complete
The corner and side elevation shows the clean edge detail — the EPDM membrane wrapping neatly over the fascia boards with no exposed joints or weak points. EPDM is our preferred flat roofing membrane for garden buildings: proven over 50 years in the industry, carrying a 20-year guarantee, and requiring virtually no maintenance once installed correctly.
The starting point — timber roof joists on the blockwork walls
This is where every roof starts — the structural timber frame. We installed the roof joists across the full span of the blockwork walls, correctly spaced and levelled to give a solid, even base for everything that follows. You can see the OSB sheets already on site and ready to go. Getting this stage right is everything; a well-built timber frame is what gives a flat roof its longevity and its ability to carry the weight of the build-up above it.
Front elevation — OSB deck complete, ready for the build-up
The front elevation with the OSB 18 deck fully laid across the joists. The exposed underside of the joists gives a clear view of the structural timber work — evenly spaced, well-fixed, and built to last. This is a proper, permanent garden building, not a temporary structure.
OSB 18 decking — the completed roof deck from above
Looking down from above at the completed OSB 18 (Oriented Strand Board, 18mm) deck — every board cut to fit precisely and fixed down across the joists, creating a continuous, rigid surface. OSB 18 is the correct specification for flat roof decking: dimensionally stable, moisture-resistant at the edges, and providing the firm, flat substrate that a bonded EPDM membrane needs to perform properly over the long term.
Vapour barrier and rigid insulation laid across the deck
With the deck down, we laid the vapour barrier first — a critical layer that prevents warm, moist air from inside the building rising up into the roof build-up and causing condensation. On top of that went the rigid insulation boards, butted tightly together to eliminate cold bridges. This is what separates a properly built garden bar roof from a basic shed roof — the thermal performance means the space stays comfortable year-round and the structure stays dry for decades.
Insulation complete — battens on, ready for the EPDM
The insulation boards fully laid and the perimeter battens in place — the roof is now ready to receive the EPDM rubber membrane. The battens define the edge detail and will hold the membrane termination neatly and securely. At this stage the roof build-up is complete: vapour barrier, insulation, and a clean flat surface for the waterproofing layer above.
OSB 18 decking — cutting and laying the roof boards
A close-up view of the OSB 18 boards being cut and fixed to the joists — each board measured, cut, and screwed down to create the tight, seamless deck needed for a quality flat roof finish.
Fully installed by our own team — no subcontractors
As with every project we take on, this Bolton garden bar roof was designed, supplied, and fully installed by our own team. No subcontractors, no handoffs — just one team responsible for the whole job from start to finish. That's how we maintain the quality and accountability our customers deserve.
Thinking about a garden bar or outdoor building in Bolton or across Lancashire?
Whether you need a roof on an existing structure or a complete garden building from the ground up, we cover Bolton, Wigan, Chorley, Preston, Blackburn, Burnley and the whole of Lancashire and the North West. Get in touch and we'd love to help you create something just as special.