Rapid setting mortar, which is easy to apply to horizontal, vertical or overhead surfaces at a wide range of thicknesses. It conforms to the requirements of BS EN 1504 Class R1 and is suitable for the rapid patching and plugging of concrete segments, concrete and brick tunnel linings, sewage systems, below ground access chambers, pipes, basements, foundations and mines.


  • Contains no chloride admixtures.
  • Excellent bond to substrate.
  • Emergency water-stopping capability.
  • Low exotherm.
  • One component, pre-bagged.

Standards compliance:

Renderoc Plug 1 and Renderoc Plug 20 comply with class R1 according to BS EN 1504-3 repair principle 3.1.

- Renderoc Plug 20: Conforms to:

  • Regulation 31 of the Water Supply (Water Quality) Regula­tions 2000.
  • Regulation 31 of the Water Supply (Water Quality) Regula­tions 2001 in Wales.
  • Regulation 27 of the Water Supply (Water Quality) (Scot­land) Regulations 2001.
  • Regulation 30 of the Water Supply (Water Quality) Regulations (Northern Ireland) 2007.

General information


Contains no chloride admixtures

Excellent bond to substrate

Emergency water-stopping capability

Low exotherm

One component, pre-bagged

Uniclass 2015

Pr_20_31_53_15 Concrete repair mortarsPrimary


C42/310 Repair mortar

Specification data - Concrete repair mortars

Product Reference

Renderoc Plug


Plug 1

1 minute initial set time (20°C).

Plug 20

20 minute initial set time (20°C). BS 6920 listed product.

Standard product features

Technical properties:

  • Bond strength by pull off (to BS EN 1542): 0.8 MPa (Plug 1, 28 days), 1.1 MPa (Plug 20, 28 days).
  • Chloride ion content (to BS EN 1015-17): 0.01%.
  • Reaction to fire (to BS EN 13501-1): Class A1.

Compressive strength (to BS EN 12190):

- Plug 1:

10 MPa (1 hour), 19 MPa (1 day), 23 MPa (28 days).

- Plug 20:

7 MPa (6 hours), 11 MPa (1 day), 45 MPa (28 days).

Similar products from Fosroc International Limited