Summary

Strandek modified an existing fibreglass (GRP) flat roof in Portishead, adding encapsulated base pads so patio guardrails could be fixed without breaking the waterproof laminate.

Project

Aim
Modify the existing fibreglass flat roof in Portishead with set-out, load-bearing bases so patio guardrail uprights can be fixed without breaking the GRP laminate.

Background
A glassfibre roof was already in place and performing as the waterproof layer. The client then needed a patio with perimeter edge protection. That existing membrane had never been detailed for guardrail posts. The work was a modification of what was already there — not a new roof and not a strip-out.

Solution
Hardwood timber cores were placed as surmounts and encapsulated in GRP onto the existing laminate. Inspect and clean the fibreglass; set out pads to the rail layout; place cores; laminate and topcoat so each pad becomes part of the parent membrane; leave receiving planes for the uprights. The original roof stayed the weatherproofing system.

Why Strandek

Strandek has installed and modified glassfibre flat roofs and GRP linings since 1976. This was a live-membrane modification, not a reroof: bond to the GRP already there, keep it watertight, and give the guardrail installer a solid base. Core work across Bristol, Portishead and the South West. Workmanship cover applies; FCA-regulated insurance-backed guarantees where specified.

Why fibreglass

GRP is seamless, puncture-resistant and bonds to itself — the right membrane for foot traffic. Encapsulated hardwood solved the load path here. A moulded fibreglass support is the cleaner long-term detail.

  • Bonds to existing GRP after clean, key and optional primer.
  • Stays watertight — no through-fix; the base is laminated and topcoated.
  • Moves with the roof — matched expansion; no rot or rust.
  • Spreads post loads and takes the same topcoat and future overlay.

Health and safety

A patio on a flat roof is an unprotected working platform. Falls from edges remain a leading cause of death and serious injury. The Work at Height Regulations 2005 require collective prevention before harnesses. HSE: falls “can be prevented by simple edge protection arrangements — a secure double guardrail and toeboard around the edge.” Construction rails: top rail ≥ 950 mm, gap ≤ 470 mm, toeboard. Permanent barriers typically 1100 mm (Part K). A painted line is not enough.

Outcome

Existing GRP roof modified, not replaced. Encapsulated surmounts ready for patio guardrail uprights. Edge protection can meet HSE expectations without a new leak path. Moulded fibreglass supports are the preferred repeat specification.