Arbosil LM

A low modulus silicone sealant, suitable for perimeter sealing of PVC-U frames.

Not recommended for overpainting or for use against natural stone.

Resistant to most alkalis and dilute acids; organic solvents may cause the sealant to swell and loose adhesion, but do not directly dissolve the material.

Very good UV resistance.

Burns, but will not readily ignite, so does not constitute a fire hazard.

Should not cause migratory staining on porous surfaces, but dirt and dust washed into or around joints by rainwater may cause pattern staining. The sealant itself may discolour in contact with rubbers, bituminous or pitch-based DPCs, etc. Contact with some metals may also cause discolouration.

Correctly applied, the sealant should not require maintenance, and has an anticipated life in excess of 25 years.


  • BS EN ISO 11600 G/F-25LM.

Health and safety:

Some components are labelled as harmful. Use of this product should be recorded in the project Health and Safety Plan.

Application temperature:

+5°C to +50°C.

Curing time:

7–14 days, depending on joint configuration and atmospheric conditions.

Joint dimensions:

- Width:

  • Minimum 6 mm; maximum 25 mm (single application), 50 mm (multiple applications).

- Depth

  • Porous substrates: Minimum 10 mm; maximum 15 mm.
  • Non-porous substrates: Minimum 6 mm; maximum 15 mm.

Joint backing:

A combined joint filler/ bond breaker, such as closed cell foam polyethylene rod, should always be used to ensure that the sealant adheres only to the joint faces and not to the back. Bond breaker tape should be used where the joint has been packed out with fibre-board.


Specify Arbo Primer 2650 for brickwork and concrete. A primer is not required for PVC-U surfaces. Primers are available to suit other substrates – refer to technical literature for details.

General information

Uniclass 2015

Pr_30_31_76_77 Silicone construction joint sealantsPrimary


L10/75 Sealant joints

L10/810 Sealant joints

L20/80 Sealant joints

L20/820 Sealant joints

Specification data - Silicone construction joint sealants

Product Reference

Arbosil LM


Black 310 ml

Brown 310 ml and 380 ml

Buff 380 ml

Dark Bronze 310 ml

Grey 380 ml

Portland 380 ml

Rustic Red 380 ml

Translucent 310 ml

White 310 ml and 380 ml

Magnolia 380 ml

Anthracite 380 ml

Light Grey 380 ml



Joint backing: Closed cell foam polyethylene rod

Joint backing: Fibre-board with bond breaker tape

Primer: Arbo Primer 2650

Product Options


Available in 9 standard colours.

Similar products from Carlisle Construction Materials Limited