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18mm Low profile solid floor panels

We are currently out of stock on that item.

RRP: £38.59

Our Price: £20.99 inc VAT

Product Details

Product Details

Our low profile panels are the perfect solution for a water underfloor heating system that is going to be used with a tiled floor. The size of each panel is 1,200mm x 1,200mm x 18mm, which will cover 1.44m2.

The 18mm low-profile system can be used for commercial and domestic applications, while the insulated panels can be put directly under floor tiles. These panels are high density XPS, making them far superior to EPS insulation boards.

To get the best use out of these items, they must be laid on suitable subflooring, which may include a screed or concrete floor, or an 18mm wooden subfloor made of a suitable material like plywood. Before fitting the panels, please read our instructions for the installation, which must be followed carefully to ensure a quality finish.

Installing the low-profile panels has been made simple, thanks to the pre-routing of the insulation panels in various patterns. The insulation boards are placed at 150mm centres, with the 12mm multi-layered barrier pipes fitting perfectly inside.

Once this has been completed, a layer of Ultra two-part levelling compound should be used. You must follow the manufacturer’s instructions for laying the floor tiles. No adhesive will be provided in the fitting pack to fix the tiles to the compound layer, which could be grey or white. Meanwhile, Ultra Proflex SP must be used to do this, although our experts will be happy to calculate the amount required.

Underfloor Heating Direct


The following is a guide on how to install solid-floor, 18mm panels for use with a water underfloor heating system. This should be used in conjunction with the instructions provided by the manufacturer.

A tiled flooring system should only be laid on a subfloor that is stable and strong enough to support it. As structures and floor substrates require various preparation methods, we recommend that any instructions are followed exactly for the preparation of substrates.

The subfloor must be prepared and ready for the use of a flexible tile adhesive in accordance with TTA guidelines. This groundwork may include more noggins as floor support, timber floors being boarded over, any adhesive residues being removed, and the use of smoothing compounds to even the subfloor.

Appropriate timber substrates

We have found that 18mm, exterior-grade plywood is suitable for this task, when fixed to secured joists at 400mm centres.

However, timber floors could be covered with 15mm exterior plywood, with the backs and edges sealed. The plywood should be screwed down at intervals of 300mm, making sure that joists or noggins support all junctions.

Appropriate solid substrates

When it comes to solid substrates, concrete that has been fully cured can be utilised, but it must be completely dry and a minimum of six weeks old. However, solid screeds will also do, if they have been cured fully as appropriate for their thickness, as according to the manufacturer’s guidelines.

If you are considering any substrates that aren't mentioned above, like calcium sulphate screeds or power-floated concrete, obtain advice from the manufacturer for priming guidelines.

Make sure the substrate is free of any grease, dirt or contaminants, as well as dust. Lay the boards loosely across the floor, numbering on the upper side so that you can identify the position of every low-profile panel. At this stage, you should have calculated the pipework runs correctly so that they reach the manifold point.


The underside of the numbered boards should be prepared using a bonding primer, specifically Ultra Floor Prime-IT MSP. Use a roller or a brush to apply a thin coat. Let the primer dry thoroughly until it resembles a clear green film. The side of the board that has been primed should not come into contact with any walls, other boards or the subfloor until ready for being bedded. It could take up to four hours to dry, depending on the conditions.

While you are waiting for the boards to dry, start to prime the substrate with Ultra Floor Prime-IT MSP, diluted with water, using three parts to one part primer and let it dry completely.

Create an adhesive base of 3mm using Ultra Tile Proflex SP, which is best applied with a notched trowel. Lay the boards onto the adhesive, primed side down, and make sure that the adhesive ridges are compressed. Be certain that the adhesive is fully compressed so that it will give a sealed base. We recommend that timber substrates are also secured using washers and screws where required, fixed at 300mm intervals. Let it dry for around four hours to make sure the adhesive is set before continuing.

Once the boards are all secure, pipework may be fitted. If possible, leave this until the next day. Once done, check the pipes for any leaks and ensure that the water pressure is correct, before tiling over. The upper side of the boards can be primed using Ultra Prime-IT MSP bonding primer. As before, use a roller or brush to apply and allow drying for up to four hours.

The finishing touches

The levelling compound should now be applied over the whole floor area, using Ultra Floor Level-IT, completely filling any gaps or spaces. The whole surface should be covered by the levelling compound, with a 5mm layer on top of the board. Wait 24 hours before tiling, longer if it is humid or cold.

Before tiling, prime using Ultra Floor Prime-IT MSP, mixed three parts water to one part primer. Once the surface is fully dried, fix the tiles in place using Ultra Tile ProFlex SP adhesive. After a minimum of four hours, apply grouting using Ultra Tile Flex Joint grout.

Afterwards, avoid walking on the surface until fully dried and settled, and don't use the underfloor heating system for at least two weeks. Then, gradually increase the temperature of the water by five degrees centigrade each day until it reaches the optimum temperature, inside the pipe, of 45 degrees.



Our delivery charges are calculated based on the weight of your entire order. Below is a table illustrating the cost for each weight bracket, please note we cap our delivery costs to a maximum of £50.

Weight From (kg) Weight To (kg) Cost
0 39.99 £10
40 59.99 £20
60 79.99 £30
80 99.99 £40
100+   £50

In addition to our standard delivery service, we can also arrange for delivery on a Saturday or before 10.30am on any working day. This level of carriage comes at an additional cost:

  • Next working day before 10.30am - Additional £5
  • Saturday - Additional £20

We can also arrange for pallet delivery on a three-day delivery, but costs vary depending on the size of the order, so please contact us for details.

Please Note: Wetroom Shower Trays will have 2 - 3 day delivery times and cannot be provisioned under our next day delivery policy.

When will I receive my order?

Orders placed before 3pm on any business day (Monday – Friday) excluding Bank Holidays should be delivered on the next business day (Excluding Saturday, unless the carriage is met) anytime up to 7.00pm.

Our standard next working day delivery does not guarantee next day delivery; however every effort is made by us and the courier to achieve this goal.

Orders taken on Friday after 3pm, Saturday or Sunday will be dispatched on Monday (excluding Bank Holidays) for delivery on Tuesday up to 7.00pm.

Orders placed on Friday before 3pm will be dispatched on Friday for delivery on Monday up to 7.00pm unless the Saturday delivery charge is met (This excludes Bank Holidays).

Please note: We rely upon the services of third party couriers and, whilst we endeavor to always deliver in a timely manner, there are unfortunately a few occasions when the couriers fail to deliver on the appointed day. This happens rarely, but because it does occur, albeit occasionally, we cannot be held responsible for the late delivery of an item, or any costs incurred by customers tradesman unable to work, please ensure you have your materials before booking in any trades.

Shipments sent outside the European Union may be subject to import duties and taxes, which may be levied once a shipment reaches your country. For details of Customs charges please consult your own Customs authorities for the latest rates.

Additional charges for customs clearance must be borne by you; unfortunately we have no control over these charges and cannot predict what they may be. We are unable to reimburse any costs incurred regardless of the circumstances.