Member since October 2026
We are polite, punctual and respectful small construction business. We take pride in all our work.
Silicone Render System Ltd is a plastering company based in Porthcawl, with over 20 years’ experience in the plastering trade. W...
Barlam Drylining Ltd are here to help customers who need an Extension Builder in CF45. We offer a competitive rate to complete all your extension b...
Need an Extension Builder in CF45? P.D.Builders has been helping local clients (20 mile radius) with their extension buildering jobs for many years...
Very reliable honest and hard working guarantee all work clean and tidy first class work
Experienced extension builder ready to quote for your work. JA Building Maintenance is the best extension builder in CF45. No obligation free quote...
Experienced extension builder ready to quote for your work. TOR BUILD is the best extension builder in CF45. No obligation free quotes and many hap...
T Porter Buiding is an established and experienced local extension builder in CF45. Please contact us for a free, no obligation quote and competiti...
Relax... you have found a reliable extension builder in CF45. Charles Marshall Contracting Ltd is a friendly and reliable company based in CF45 who...
Sharif General Builder is an established and experienced local extension builder in CF45. Please contact us for a free, no obligation quote and com...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in CF45 it ranges from £1,400 (A.Gaddarn Builders based in NP11) to £4,280 (Silicone Rendering Systems Ltd based in CF36).
Comparing extension builders estimates for fitting an RSJ gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
Get rates and quotes to install an RSJ in CF45 by posting a job with HaMuch and we will send it to extension builders in CF45.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Rhondda, Cynon, Taff | £31 | £209 |
| Install An RSJ near Rhondda | £31 | £206 |
| Install An RSJ near Pontypridd | £33 | £211 |
| Install An RSJ near Aberdare | £32 | £212 |
| Install An RSJ near Merthyr Tydfil | £33 | £220 |
| Install An RSJ near Church Village | £34 | £214 |
| Install An RSJ near Tredegar | £30 | £217 |
| Install An RSJ near Caerphilly | £33 | £208 |
| Install An RSJ near Ebbw Vale | £30 | £217 |
| Install An RSJ near Risca | £32 | £218 |
Whether you’re looking to extend your kitchen with a side return extension or you want to convert your basement into a liveable space, read our cost guides to get an idea of how much each project costs before getting a more accurate quote from our database of reliable tradespeople.

Underpin a building - £17,487

Two storey extension - £87,981

Build a timber frame extension - £25,987

Build a swimming pool - £80,987

Single storey extension - £54,744

Side return extension - £41,356

Install an RSJ - £2,187

Outbuilding - £9,987

Build a Mansard loft conversion - £51,987

Loft conversion - £33,630

Build a kitchen extension - £41,987

Hip to gable loft conversion - £41,987

Granny annexe - £86,987

Garden office - £9,987

Convert a Garage - £15,987

Garage - £18,487

Build a flat roof extension - £21,987

Build a dormer loft conversion - £41,987

Concrete foundations - £6,237

Convert a bungalow loft - £28,987

Convert a basement - £37,356