Thermally Enhanced Bentonite

Thermally Enhanced Bentonite

Thermally Enhanced Bentonite – HeatSeal

Now improved even further, Offering 2.15 w/mk performance!

Totally UK sourced & manufactured product

Product verified by an independent UK based test house

A blend of quality assured raw materials, used in conventional Civil Engineering Applications specifically formulated for use in Geothermal Heat Pump Grouting Technologies including Ground heat source loops. Offers ease of mixing, combined with low shrinkage and excellent sealing.

Once mixed with water it remains slightly soft and plastic, thus insuring continued flexibility to cope with any ground movement and maintain contact between the ground and probes.


The mixed product offers good pumpable qualities, good flow characteristics, and is designed to provide a high Thermal Conductivity Performance having been independently tested to provide a 2.15 w/mk performance and provides the following attributes :-

  • Quality assured manufacture
  • UK produced – low carbon footprint
  • Non setting
  • Single bag product eliminates on site blending
  • Easy to mix
  • Fast equipment clean down time
  • Consistent /easy pumping performance and flow
  • High thermal conductivity
  • Low permeability – 3.5 x 10-11 m/sec
  • Supplied in 25kg bags

The product is supplied in dry powder form. It is a single bag solution ensuring accuracy in materials usage, with each bag requiring only the addition of water together with a suitable mixing process.

If you prefer, we can of course provide the Bentonite in PURE form (i.e. to be mixed with sand at site).

Proven Quality

For a copy of an independent 3rd Party Thermal Conductivity Test on our HeatSeal product please give us a call.


For use in the filling of Geothermal Boreholes, including areas of Over break.
Properly mixed HeatSeal has excellent pumping / placing characteristics over long distances, and over prolonged periods.


The product is supplied in dry powder form, and represents a single bag solution to the Geothermal Grouting processes, therefore ensuring accuracy in materials usage, with each bag requiring only the addition of water together with a suitable mixing process.

To obtain 2.175 W/mK the product should be mixed with water at a 0.28 water / solids ratio. (Equivalent to 5.6 litres per 20kg bag water solids ratio).

OR to obtain 1.9 W/mK the product should be with water at a 0.33 water / solids ratio. (Equivalent to 6.6 litres per 20kg bag water solids ratio).

Packaging and Storage

Palletised material should be stored clear of the ground, sheeted and preferably under cover.

The pallets should not be stacked more than two high with the material being used on a first in, first out basis.

The shelf life for the product is 6 Months from receipt of purchase if stored correctly.


HeatSeal is randomly tested in accordance with specific procedures to ensure compliance to specification prior to despatch and are subject to the controls of a BS EN ISO 9001 approved quality system.

Health and Safety information

When mixed with water HeatSeal may cause skin and eye irritation.

We therefore advise the use of barrier creams, gloves and protective eye wear as a precaution when using these products.

A further detailed CoSHH Health and Safety Data Sheet for this product is available on request, please call our office number 01388 720228.

Final Word

Some people favour geothermal grouts with cement content. We avoid this because of the risk that future ground movement or drying out of a rigid pile of grout could lead to the double-whammy of:

a) Loss of contact between the ground formation and the grout and or the grout and the loops and hence total break of conductivity.

b) Contaminated surface water running down the gap between the formation and the rigid pile.

Reader Grount – Part of the Langley Group

Go Geothermal Ltd look to support UK Manufacturing and our Thermally Enhanced Grout is wholly produced in the UK.

We have an exclusivity agreement with Reader Grout (part of the Langley Group) to promote and distribute their Thermally Enhanced Grout.

Allied to supporting UK manufacturing this also allows us all to reduce our carbon footprint.

Used by leading edge companies this Thermally Enhanced Grout provides excellent Thermal Conductivity specifically engineered for Ground Source and gives excellent pumpability.