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Local and County Sligo orders made before 12.00 pm Wednesday 21st December will be delivered before 1.00 pm on Friday 23rd December. All nationwide orders made before midnight on Monday 19th December will be dispatched prior to Christmas. All orders made after that will be processed from 3rd January onwards. Happy Christmas!

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PIR Insulation Unilin Full Fill Cavity Wall Insulation 100mm

54.75 (Inc. VAT)

Bulk Product
Delivery time: 3-5 Days
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Unilin (previously Xtratherm) CavityTherm PIR Full Fill Cavity Insulation (CT/PIR) 100mm

Key features:

  • High performance
  • Trusted brand
  • 100mm thick and 2.16 sqm coverage per pack
  • Ideal for Trades people and for DIY
  • Unilin was previously known as Xtratherm

26 in stock (can be backordered)

Product Description

Unilin (previously Xtratherm) CavityTherm is a continuous wall insulation system. It delivers ultimate thermal performance with the added assurance of inbuilt protection from wind driven rain.

It is a high performance composite board of enhanced PIR with a lambda value of 0.021 W/mK, for full fill cavity wall applications. CavityTherm has gas tight facings with one face bonded to a profiled HIPS skin during manufacture to provide a drainage plane.

Each pack gives coverage of 2.16m2. There are four boards per pack and each board is 1200mm x 450mm.

Unilin (previously Xtratherm) CavityTherm key features:

  • Engineered HIPs facer provides wind driven rain protection
  • Moisture redirected to outer surface
  • Prepositioned slots for sloping wall ties – no creep
  • Fully engineered jointing
  • Full range of accessory pieces build continuous system
  • Excellent Thermal Bridging Values
  • Continuous insulation layer
  • Minimal cavity width requirement
  • No need for engineer’s report
  • Ultimate U-values & meets standards
  • See the Product Brochure and Installation Guide here
  • See the Agrément Certificate here
  • See the Specification Clause here
  • See the Declaration of Performance here
  • If you require very large quantities then you can call us on 0818 888 000 or open up the live chat on our website and we can provide a separate quotation for very large quantities.
  • Thermal conductivity is 0.021 W/m²·k (BS EN 13165:2008)
  • Typical R Value of this 100mm version is 4.52

Unilin (previously Xtratherm) is a built-in insulation system that achieves ultimate U-values within traditional wall constructions. It doesn’t require an engineer’s report, meaning that minimal heat energy is lost through the walls.

Meeting A+ or Passive standards within a 100mm cavity width, CavityTherm builds as a system to provide a continuous insulation layer that you can see is installed accurately. It provides an affordable and practical solution when looking to buy best performance wall insulation.

CavityTherm’s unique engineered profiled facing directs any moisture that might penetrate the external wall down the protective facing and back onto the external leaf, giving added protection from wind driven rain. The board includes specifically designed rebated edge detailing on all four edges to allow the system to tightly interlock when installed. This engineered jointing of the insulation layer ensures continuity and results in excellent thermal bridging detailing.

CavityTherm’s unique engineered profiled facing directs any moisture that might penetrate the external wall down the protective facing and back onto the external leaf, giving added protection from wind driven rain.

The board includes specifically designed rebated edge detailing on all four edges to allow the system to tightly interlock when installed. This engineered jointing of the insulation layer, with the addition of bespoke ancillary pieces to insulate effectively around services such as hockey sticks, meter boxes and corner details, ensures continuity and results in excellent thermal bridging detailing.

Typical Physical Characteristics:

  • Density 30 kg/m3
  • Compressive Strength >100 kPa @ 10%
  • Thermal Conductivity 0.021 W/mk
  • Service Temperature -20 degrees C to +100 degrees C

The profile edge of the boards allows wall ties to be positioned sloped down to the outer skin, whilst acting as a template for mortar on the inner skin. Unilin (previously Xtratherm) CavityTherm has gas tight facings – with one additional face bonded to provide a drainage plane, directing moisture onto the outer leaf.

Unilin (previously Xtratherm) CavityTherm’s specially designed profile maintains a residual channel, protecting the structure.

Installing Unilin (previously Xtratherm) CavityTherm gives U-Values that are indicative of targets set to achieve the higher levels of the Code for Sustainable Homes – but within traditional construction allowing the architect to design low carbon homes and maintain an overall cavity width of 100mm.

Frequently asked questions:

What is CavityTherm?
Unilin (previously Xtratherm) CavityTherm wall insulation board is a high performance composite board of PIR core with a lambda value of 0.021 W/mK. The boards have gas tight facings with one face bonded to a profiled HIPS skin during manufacture to provide a drainage plane. CavityTherm’s unique profiled facing directs any moisture that might have penetrated the external wall down the protective facing and back onto the external leaf. The board includes specifically designed rebated edge detailing on all four edges to allow the system to tightly interlock when installed.

What is the real benefit of using CavityTherm?
Put simply, the U-Values achieved by placing CavityTherm into your standard 150mm cavity meets the Passive House standards for Ireland. It builds as a ‘system to ensure continuity. You can physically see that the procedures on site are being followed. It’s a very practical, affordable solution to low energy design.

What wall ties do I use with CavityTherm?
Standard S/S wire wall ties are used with CavityTherm. At up to 5 ties/m2  the thermal impact is negligible because the cavity is kept to a reasonable width. Pushing the cavity wider and adding greater amounts of insulation will necessitate low conductivity ties, and result in worse thermal bridging at junctions. It is for this reason that a U-Value of around 0.15W/ m2K is seen as optimum by regulations.

Why slope the wall ties down to the outer face?
This is not specific to CavityTherm, all wall ties in any construction should slope slightly down to prevent water travelling along the wall ties into the construction. Wall ties must be kept clean and free of mortar.

What thicknesses of CavityTherm are available?
CavityTherm is manufactured for 100mm,125mm and 150mm cavities, and achieves U-Values as low as to 0.12 W/m2K.

What building types can use CavityTherm?
CavityTherm can be used in new external masonry cavity walls up to 25m in height in domestic and non-domestic buildings.

CavityTherm has a lot of accessories as part of the ‘system’, what are they for?
An excellent wall U-Value is not the only item that must be addressed to achieve a Low Carbon Fabric. Airtightness and thermal bridging must also be improved. Thermal Bridging is in fact just ‘good detailing’ and is accounted for in SAP. Xtratherm is the only insulation board manufacturer that addresses gaps or breaks within the continuity of the insulation layer.

How do you detail insulation around stepped cavity trays, periscope vents in suspended floors or at corners, or meter boxes?
Xtratherm has developed bespoke insulated pieces to ensure that these details are well insulated so as to avoid thermal bridging and possible condensation mould growth.

Is there a benefit in the ‘Engineered edge detail’?
The Building Regulations now ask that insulation systems be ‘continuous’ and are installed in accordance with accredited detailing. The jointing system in Xtratherm products achieves this, encourages a more accurate build, and avoids the 0.01 U-Value penalty that should be applied when calculating to BR443.

When a board is cut what tape do I use to make the join?
When two abutting boards are to join, cut the profiled edge from each board and ensure that they are closely butted. The joint should be sealed. When building the inner leaf first – seal with a waterproof tape. The tape should be applied to a dry surface. When building from the inside a preparatory self adhesive jointing strip is available to insert over the join. Any penetrations or small repairs can be made with the tape or sealant. Any services running through the insulation layer should be sloped to the outside. DPCs should be dressed over services as per Eurocode 6.

You recommend the use of a ‘Cavity Board’ – what is that?
The use of a cavity board is recommended during construction. It is a board that is placed over the installed boards as the inner leaf is raised to catch any mortar drops that might fall. If mortar does fall onto the upper edge of the CavityTherm the HIPS skin is easily cleaned with a damp cloth.

If you need any help with this Unilin (previously Xtratherm) Cavity Fill solution then just call our helpful and friendly team today on 0818 888 000 or open up the live chat and we will help in every way we can.

  • Note: Delivery of this bulky product is available Nationwide but will be subject to a bulk delivery charge. Delivery charges are calculated during checkout according to the delivery address provided.

Should you require very large volumes of this product then we may be able to improve your delivery charge. To discuss this you can call us on 0818 888 000 for more information and to confirm pricing.


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Delivery charge information:

You can add any and all products to the basket and calculate your delivery charges easily. Simply enter your Eir Code and all applicable charges will be calculated automatically.

  • Orders of €150 inc VAT or over will get free delivery nationwide. (Please see notes below for exceptions)
  • All orders under €150 inc VAT incur a standard delivery charge of €10 including VAT
  • (Please see below for exceptions)
  • We deliver to anywhere in Ireland.

Bulky items:

Bulky items may incur delivery surcharges (see below) as extra courier costs unfortunately are often unavoidable. If the order is over €150 only the bulk delivery charge will apply. The final delivery charge for bulky products will be calculated when all items have been added to the shopping cart.
All efforts are made to indicate where products are subject to delivery surcharges.

Special Order items:

We are in regular contact with our suppliers and we try our best to make sure that all “special order items” on our webstore are available from our suppliers within the timeframe advertised. If, for some reason our supplier is out of stock and you have ordered the product we will let you know immediately and give you the option to either wait until it’s back in, upgrade to a better model at little or no extra cost or receive a full refund. See more info on Special Order products here.


All nationwide deliveries will be delivered within 2-3 working days.

(Local deliveries within 1-2 working days.)

Special order items may take longer to deliver but this will be indicated on the product information page. You can see more info on Special Order products here.

Working days are Monday through Friday excluding public holidays. Orders placed on Saturday/Sunday will be deemed as being placed on the following Monday.

Some items may take longer to ship. If this is the case, we will notify you by phone/email of this delay.

If your delivery is urgent please contact us by phone or email and we will do our best to expedite it.

Please indicate on your order any specific delivery instructions.

Bulky goods:

Bulky goods will be delivered on pallets and will be unloaded by the courier. All bulky goods are delivered kerbside. Unfortunately, the delivery company will not convey the goods into premises for storage unless agreed in advance. Access to the delivery location must be suitable for a truck and failure to provide suitable level ground for operating pallet truck may result in refusal to deliver by the courier. Please note delivery operators will apply safe procedures in relation to ongoing Public Health considerations..

Exceptional Goods:

Some building materials are extremely bulky and not practical to deliver outside Co. Sligo e.g. concrete blocks, tonne bags of sand or gravel or some lengths of timber. We have highlighted where this is the case in bold red writing. If you do order these products we will contact you to see if you want to pay an additional delivery charge or if you wish to cancel the order. Please do not take offence to this as some bulky goods may cost much more to deliver than the value of the goods. We are based in Sligo so can offer a local delivery service in this area using our own vehicles.

If there is a forklift or teleporter available onsite, we would appreciate if you could tell us in advance by filling out the special delivery notes when completing the order.

The Seller or the courier company will not be held responsible for any damage to goods or persons caused by the goods being unloaded by the buyer.

**Please contact us in advance of ordering if unsure of the above**

Damaged goods:

Where goods are damaged on delivery the Buyer has the right to refuse delivery. Damaged goods should be photographed on delivery and photos emailed to straight away. If goods are damaged on delivery, we will replace the goods in as timely a manner as possible at no extra cost.

Once the goods are signed for it will be deemed that goods were in good state when delivered.


Delivery shall be within a time period agreed between the Buyer and Seller and the Seller shall use its best endeavours to ensure that delivery takes place within the period agreed. Failure by the Seller to deliver the Goods within the agreed time period shall not amount to a breach of this contract by the Seller and the Buyer shall not be entitled to damages or other compensation or to cancel this contact by reason of such failure.

The Seller reserves the right to deliver in instalments. Each part delivery shall be deemed to constitute a separate contract, the fulfilment or non-fulfilment of which shall not affect any other part of the contract or the contract as a whole. Where any order involves more than one delivery and default is made on payment on the due date (either under this contract or any other contract made between the Seller and the Buyer) the Seller shall have the right to suspend all further deliveries until payment is made or to terminate the contract without prejudice to any existing claim.

The Seller shall not be liable to the Buyer for any loss or damage which may be suffered by the Buyer as a direct or indirect result of the supply of the Goods by the Seller being prevented, hindered or delayed by reason of any circumstances whatsoever which are outside the control of the Seller. Once delivery has been accepted the Buyer shall not be entitled to withhold or postpone payment of all or any portion of the price agreed, therefore.

1. Where goods are damaged on delivery the Buyer has the right to refuse delivery. Damaged goods should be photographed on delivery and photos emailed to If goods are damaged on delivery, we will replace the goods in as timely a manner as possible at no extra cost.

2.  If goods are signed for and later found to be faulty/damaged, notice must be given in writing within 24 hours and photos will be required to be emailed to

3. All faulty/damaged goods issues will be dealt with on a case by case basis and best endeavours will be made to rectify within a timely manner. Manufacturers’ warranties will apply in certain cases.

4. Any returned items which are not faulty or damaged will incur full carriage costs which must be paid for by the customer.  Notice of intention to return unwanted goods must be given within 14 days of receiving goods. Returned goods must be in original packaging and in original condition before refunds can be given.

5. All returned goods to be sent to Patrick Rogers Ltd., O’Connell St., Ballymote, Co. Sligo

Note regarding Oil Boilers and Boiler stoves:

Please ensure you check with us first or consult a qualified professional before ordering your oil boiler or boiler stove to ensure you order the correct one for your home. If the product needs to be returned a restocking fee may apply.

Returns of Special Order Items

All “special order items” are subject to the same product returns policy as stocked items. However, items which are returned that are not faulty or damaged on delivery will be subject to a 10% restocking fee.

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