Lime Render Surface Guide

Brick: Use Limecote as a finish coat over Warmcote. trowel apply and finish with a flexible trowel or flexible blade such as Speedskim.

Block: As above, if the blocks are lightweight (3.6N or less), wet in well, to reduce suction. Always try a sample first to test the adhesion/bonding strength.

Stone Rubble: If the intension is to follow the undulations of the background, then apply Limecote directly onto the background and finish with a short flexible trowel or blade. If there are deep areas to dub out, Limecote could be used as a stiff mix (less water addition) or deep areas could be filled with Warmcote, this will be faster setting and less dense.

Timber Lath: Apply Warmcote to 10mm over the face of the lath, lightly scratch with a render scratching comb, being careful not to cut too deep. Allow to set, though not necessarily dry, on larger areas, it is worth getting the Limecote finish on while the Warmcote is still ‘green’, this will give greater suction control and more time to finish. Externally, apply an 8-10mm Limecote finish, internally, this can be reduced to 5mm or less. Finish with a flexible steel trowel or blade such as Speedskim.

Clay Backgrounds: The most traditional and historic building material, please see our separate download on clay backgrounds.                                                                                                                 Preparation is important, remove as much loose, friable material as possible, depending on how damaged the clay is, it may not be possible to remove all loose pieces, ideally dust free should be good enough. Mix up an hydraulic limewash, ideally using NHL2, (NHL3.5 is ok) and clean water to the consistency of milk.. Lightly damp the clay background with a pump spray and work the limewash well into the clay. This will consolidate the clay and also add an element of suction control.

As with stone rubble backgrounds, Limecote could be used directly, if the intention is to preserve the uneven, rustic nature of the substrate. A 20mm minimum will be required externally, internally less than 8mm is possible.                                                                                                                       If the requirement is for a straighter, flatter finish, or if there are deep areas that need filling, then a base coat of Warmcote would be recommended. Warmcote will not shrink, even at great depth, so it is possible to deep fill to 150mm+ in one pass using a stiff (less water addition) mix and go straight over with a scratch coat. As with lath, allow to pull in and harden, though not necessarily  dry, then apply Limecote and finish with a flexible trowel or blade.

 

Plasterboard: Limecote can be used over plasterboard to achieve the visual softness of lime plaster. However, as plasterboard is designed to carry a thin coat of fast drying gypsum, it is recommended that the board be primed with a liquid primer such as Sovereign Plasprime Green, this will stop the moisture soaking into the board and reduce the risk of warping.

Skimming Historic Plaster: Limecote can be applied over historic plaster, providing a new finish, but conserving the historic fabric of the building. Remove loose, friable and dusty material, with special attention to washing off soft powdery distempers (whitewash). Gently damp down and apply Limecote into thin passes. Finish with a flexible steel or plastic trowel.

Wood Wool Boards: Apply 100mm jointing tape to the board joints and trowel in with a thin spread of Limecote. Internally, mix one bag of Warmcote with 1/3 of a bag of Limecote, this will allow a single coat application 8-10mm thick, the Warmcote will cover the plastic washers and give an element of insulation, the Limecote addition will give a creamy, fattier plaster to finish.              Externally, apply 12mm of Warmcote, allow to harden, though not necessarily dry and a finish with 8-10mm of Limecote.

Straw Bale: Limecote can be sprayed onto straw bale using a small hopper and a 3hp ‘workshop’ compressor. The first application should be quite liquid and sprayed well into the straw as a primer/pricking up coat. Allow to harden off, then spay a second coat of Limecote. Limecote is not sensitive to variations in depth, so dubbing out or straightening can be carried out by just lingering a little with the spray over areas that require filling out. The second coat could be finished with a short flexible straight edge, or flexible steel or plastic trowel. Straw bale buildings are usually finished in a visually soft, organic way, showing the undulations in the substrate. If a straighter finish is required, a third coat could be spray or hand applied and further straightened out.

Wood Fibre Boards: Most available board systems have tongue & groove edges, so a mesh or jointing tape, is not necessary. However, where boards are cut and the tongue & groove is lost, for instance on internal or external corners, then a mesh, such as an alkali resistant render mesh or hessian should be bedded in with Limecote and span the joint by at least 150mm. Allow the meshed areas to dry and apply a scratch coat of Warmcote, 12mm externally 8mm or less internally. Once hardened, but not dry, apply a finish coat of Limecote, 8-10mm externally and 5mm or less internally.

Sprayed or Hand Placed Hemp: Hemp provides an excellent low carbon, insulated building material. Internally it can be finished with a skim of Limecote applied directly. Externally either 20mm of Limecote applied in two 10mm coats, or 12mm of Warmcote, with an 8-10mm Limecote finish.

Reed: Either new reed board or historic reed can be plastered with two thin coats of Limecote internally, or a Warmcote scratch coat with Limecote finish. Externally 12mm of Warmcote with an 8-10mm finish of Limecote.