From £24.50 + VAT per bag

Breathable render for EWI – Baumit OpenContact contact mortar

Baumit OpenContact contact mortar is:-

  • is an easy to use, natural white, breathable, contact mortar.
  • an adhesive mortar for facade insulation.
  • the adhesive coat and base coat for the Baumit Open EWI system.

Product overview

Where is it used?

  • Baumit OpenContact can be used to bond EPS boards to masonry surfaces and as the base coat for the render system.
  • It can, with Baumit StarTex fibre glass mesh, be used as a base coat for render carriers.

How is it used?

  • Baumit OpenContact comes in 25kg bags and is best mixed, using clean tap water, with a plaster whisk to a smooth lump free consistency.
  • This should be left for 5 minutes and then re-mixed and gives a working time of around 1.5 hours.
  • OpenContact can also be spray applied with a continuous mixer.

How much will you need?

  • Baumit OpenContact has a density of 1.35kg per mm per m² (1mm thickness of plaster over 1m²). Each 25kg bag will cover up to 4m² at 4-5mm thickness as a base coat and 5m² at 3-4mm thickness as an adhesive coat.

Frequently asked questions

How long does it take to set?

Setting times vary with temperature and humidity but in the summer the product will usually stiffen enough to finish in a few hours and set hard overnight. In winter stiffening may be extended to more than one day with hardening more than two days.

Technical details

Pricing & shipping

This product will require one pallet space and so shipping is likely to cost between £50 and £100, depending on where you live. Contact Us for a more accurate costing.

Bag weight (kg) Coverage [m²]Single bag costFull pallet bag cost

Book your free project consultation

We’d like to hear from you. Call us on 01392 861763 or email us at with any questions or comments.

If you can’t seem to find what you need on our website or you have large quantities of materials to purchase please contact us for a chat and we’ll offer you a more bespoke solution.

We’re normally open from 8.30 am to 5 pm Monday to Thursday, and 8.30 am to 1pm on Friday.