Are thermal calculations done in the same way for all building elements?
Generally speaking, yes - all calculations are done by the 'combined method'. However, ground floors differ slightly from other building elements in the information that is required. If requesting a calculation for a ground floor, please ensure that you provide a floor area and length of the exposed perimeter (i.e. the length of new floor along outside-facing walls). This allows us to calculate a perimeter/area ratio, which is crucial in the floor calculation.
Can a breather membrane be laid directly over Recticel's insulation boards?
Different breather membrane manufacturers have different guidelines for their products, and these should always be consulted prior to installation. It may be possible to lay the breather membrane on the insulation, but with a counter batten airspace above.
If you would like to discuss application of any specific project, please contact our Technical Services.
Can I get a U-value calculated for my project using Recticel Insulation products?
Absolutely! Please contact our freephone technical helpline on 0800 085 4079 or use our free of charge U-value calculator here.
Can I recess cables into Recticel PIR insulation boards?
Cables should not be recessed into the insulation boards. They may be laid between two layers of boards with the cabling oversized to accommodate for an increase in operating temperature. If cables penetrate an insulation layer, PIR will have no detrimental effect on cable sheathing.
Further guidance on the above should be obtained from a qualified electrician.
Can I recess downlighters into Recticel PIR insulation boards?
General best practice in such scenarios would be to include for a battened service zone to avoid compromising the performance both the insulation and the vapour control layer. The required depth of this “void” should be determined by the requirements of the specific lighting manufacturer.
If this is not suitable and the lighting needs to be recessed, then advice should be sought from the downlighter manufacturer.
For more information regarding this, an information document can be found within the IMA Resource Centre on the 'Use of downlighters, recessed lights or spotlights and PIR PUR insulation' here.
Can I say a product is "CCPI-assessed" even if I can't display the mark?
Yes, as long as it's accurate and reflects our current published status. Just don't reproduce the mark itself or imply your company holds an assessment it hasn't gone through.
Can I use the CCPI mark on my own website?
Not our product mark, no. Manufacturer marks and Merchant & Distributor marks are two separate things under CCPI. If you want your own CCPI mark to display, you'd need to complete the separate four-clause Merchant & Distributor assessment yourself. See the note above for more detail.
Can insulation be placed between and over flat roof joists?
BS 5250:2011, the British Standard for the control of condensation in buildings, does not recommend installing insulation between timber joists as well as above the deck.
However, not all hybrid roofs will show condensation risk, our Technical Services team will be happy to assist with U-value calculations and condensation risk analysis where required, we will also discuss the potential risks involved, but please note all calculations will be marked “NOT RECOMMENDED” inline with the British Standard.
Can PIR insulation boards be used directly below flooring tiles?
No, PIR insulation boards should not be used directly below flooring tiles, a suitable substrate such as screed should be used to distribute the load and prevent movement and cracking of the tiles.
FHS: Is there a transition period for projects already underway?
Yes. Transitional arrangements apply until 24 March 2028 for most new homes and until 24 September 2028 for relevant higher-risk building provisions. Projects with a valid building control application submitted before the Future Homes Standard comes into force may continue under the previous standards, provided they meet the applicable commencement requirements.