Replacing Corroded Steel with GRP
Rusted steel grating, handrails and stair treads can be replaced with GRP, which does not corrode, often on the existing steel frame. At UIS, we survey, fabricate and install the replacement GRP with our own site teams.
Can corroded steel walkways be replaced with GRP?
Yes. Where the steel frame is sound, we replace rusted steel grating, handrails and stair treads with GRP fixed to the existing frame. GRP does not corrode, so the area does not need recoating again.
If steel walkways and platforms are rusting in a wet, coastal or chemical area, you can recoat them, and do it again in a few years, or replace them with GRP while the area stays in use.
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Often on the existing frame
Where your engineer confirms the frame is sound, we fix the new GRP grating and handrails to it, so the frame stays in place.
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Lighter on an older frame
GRP weighs roughly a fifth of the steel equivalent, so swapping steel grating for GRP reduces the dead load on the frame. GRP is less stiff than steel, so your engineer also checks it does not bend too much over the existing spans.
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Replaced in sections
We replace one section at a time so a route stays open. The GRP is cut to size in our workshop, and any trimming on site is done under dust extraction, with no hot-works permit needed.
How we replace steel with GRP
What we check before we replace anything, what we replace, and what decides whether the frame can stay.
What we check before we replace anything
- whether the support frame is sound enough to keep (your engineer's decision)
- the openings, spans and bearing on the existing steel
- how much the GRP will bend over those spans: GRP is less stiff than steel, so it is often deeper than the steel grating it replaces, or the frame needs extra bearers
- the load class the area needs now, which may be higher than what was there before
- how the area can stay in use during the work
- the fixings, which are grade 316 stainless steel
If the frame is too far gone, we make a new one in steel or GRP and replace the lot.
- Grating
- GRP grating cut to the existing openings
- Set by: The span, load and bearing on the frame
- Handrails
- GRP handrail on existing or new posts
- Set by: The BS 6180 or BS EN ISO 14122-3 load class
- Stair treads
- GRP anti-slip treads over sound stairs
- Set by: The condition of the stair
- Whole stairs and platforms
- New GRP or steel where the structure has gone
- Set by: Your engineer's assessment
We price replacement from a survey. These are the main things that affect the price:
- the area of grating and length of handrail
- whether the frame stays or is replaced
- phasing to keep the area in use
- access, permits and working hours
- taking away the old steel
Our GRP product pages
Each of these has its own page with the full specification.
From survey to handover.
We survey, detail, fabricate and install the GRP ourselves, so one company is responsible for the whole job.
Survey and measure
We survey the existing walkways, record the openings and the condition of the frame, and agree the phasing with you. On an existing structure we can 3D-scan it, so our drawings match what is on site.
Drawings and quotation
Our draughtsmen detail the GRP and any support steelwork to the loads your structural engineer gives us. We then send an itemised quotation that includes fabrication and installation. On major commercial packages the quotation comes back within 1 to 2 weeks.
Fabrication
We fabricate the support steelwork and cut the GRP panels and sections to size in our Rotherham workshop, so most of the cutting is done before delivery.
Installation
Our own site team installs the GRP under an SSSTS-qualified supervisor, to a method statement written for the job. We cut the GRP to size in our workshop, so there is little cutting on site. Where a panel does need trimming, we cut it with a diamond blade under dust extraction, away from live areas where possible, and no hot-works permit is needed.
Handover
At handover we give you the O&M pack, with the manufacturer's test data for the products we installed. The 12-month defect liability period runs from practical completion, in line with standard JCT terms, unless your contract sets different terms.
Why replace with GRP instead of recoating
Recoating steel has to be done again every few years. GRP does not corrode, so once it is fitted there is no coating to redo, and at roughly a fifth of the weight of steel it reduces the dead load on an older frame.
Request a quoteGrating panels and finishes.
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01
Grating and walkway decks
We replace rusted steel grating with GRP grating cut to the existing openings, fixed down with grade 316 stainless steel clips so the fixings do not corrode against the new deck.
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02
Handrails and guardrails
We replace corroded handrails with GRP handrail to the load class for the area, on the existing posts or on new ones.
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03
Stair treads and stairs
We fix GRP anti-slip treads over stairs that are still sound, and replace whole stairs in GRP where the stringers have gone, with handrails both sides.
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Installed by our own site teams
Our own site teams install every job. Each job has an SSSTS-qualified supervisor, every operative holds a CSCS card, and the teams are PASMA and IPAF trained. We write a method statement for each job and plan the work around your site, out of hours where your programme needs it.
"I've worked with UIS for several years on some high profile and very complex projects. Their attitude and work ethic are second to none - providing high quality services and products which are delivered safely and on time every time. Overall they are a pleasure to do business with and wouldn't hesitate recommending UIS for any steelwork or metalwork packages."
Questions we get asked.
Often, yes, if your engineer confirms the frame is sound and the spans and bearing suit the depth of GRP grating. We survey the frame and the openings first. GRP is lighter than steel grating, so it reduces the dead load on the frame, but it is much less stiff, so it bends more over the same span. The new GRP grating is often deeper than the steel it replaces, or the frame needs extra bearers, and your engineer checks the deflection.
Grade 316 stainless steel clips and bolts. Mild steel fixings would corrode against the new GRP.
Usually, yes. We replace one section at a time so a route stays open. The GRP is cut to size in our workshop, and any trimming on site is done under dust extraction, with no hot-works permit needed.
Recoating can cost less on the day, but it has to be done again, and recoating over a process area is work at height in itself. We can price both so you can compare.
Taking out and removing the old steel is part of the job we price, so you are left with the new GRP and nothing to clear.