Find a builder to make your building structurally sound

RSJs support your new extension or other construction to ensure that your property is structurally sound. They are crucial parts of your building work that mustn't be ignored, and must be installed by a professional. 

Install an RSJ cost in CM18 - Sort by rates or availability

From £2,080

Member since August 2025

Get quotes

Can design and Construction

Erald Kanani

Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

From £2,392

(last active 07/10/26)

1 review

Get quotes

Torrington

Torrington Design

NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...

"Did callout made safe my elctrical work thanks" - reviewed 16/05/23, REECYRUSSO

From £3,784

(last active 07/10/26)
Get quotes

Propello

Ali Alagoz

Propello is an established and experienced local extension builder in CM18. Please contact us for a free, no obligation quote and competitive rate...

From £2,760

(last active 07/10/26)
Get quotes

Rafix Building

Rafal Szczepanski

Our homes need to be regularly maintained and from time to time they need to be rejuvenated, modernised and enhanced. When it comes to building wor...

From £2,368

(last active 06/10/26)
Get quotes

Best Builders

Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

From £2,632

(last active 06/10/26)
Get quotes

MM-Builders

Shelim Miah

Maintenance and repair 

Family run business from 2006

 

 

From £2,296

(last active 06/10/26)
Get quotes

KS Plastering SERVICE

Sampson Essien

Thistle Bonding Coat: Ideal for use on low-suction backgrounds such as brick or concrete blocks, this product provided a solid foundation, Thi...

From £4,520

(last active 05/10/26)
Get quotes

Reid and Co Developments Ltd

Jay Reid

We are a well established buildng firm who have been providing building services and managing of projects now for 25 years. We have all the necessary ...

From £2,592

(last active 04/10/26)
Get quotes

Samuele Paolini

Samuele Paolini

Need an Extension Builder in CM18? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...

From £2,224

(last active 02/10/26)
Get quotes

SH Enterprise

Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...

RSJ cost in CM18

Estimates for install an rsj near CM18

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in CM18 it ranges from £2,080 (Can design and Construction based in Ig11) to £4,520 (Reid and Co Developments Ltd based in NW8).

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 CM18 by posting a job with HaMuch and we will send it to extension builders in CM18.


Get extension builder rates instantly

Estimates for common extension builder jobs in CM18;

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.

More extensions & conversions cost guides...