5 minute read
- Old buildings tend to have shallow rafters, so how do we insulate to modern standards? TLX Gold has the answers…
- TLX Gold multifoil insulation doesn’t need to be counter-battened, therefore you don’t need to raise the roof height
- TLX Gold is a trusted, BBA approved insulating breathable membrane
Shallow rafters are a typical feature of old buildings; a sacrifice some homeowners are willing to make in favor of preserving character over practicality, but what happens when the winter draws in and nights get longer and colder? With shallow rafters unable to accommodate adequate insulation to keep the building warm, these roof structures aren’t conducive to year-round comfortable living conditions. So, many builders and end users look for products that can offer the greatest level of roof insulation, without having the complication of deep roof build-ups which compromise on internal head space.
U value restrictions
U value requirements have tightened over recent years, meaning no single product can achieve current building regulations on its own. PIR board or mineral wool would take up far too much room within the roof space, and although multifoils tend to be thinner, they don’t meet current standards by themselves. Therefore, it is advised to utilize a hybrid system, using a multifoil insulation alongside mineral wool.
Insulation materials
PIR board
PIR board is reflective, has a low thermal conductivity, and holds air still. It is specified in-between rafters, but to ensure an airtight fit, it needs to be cut to the size of the rafter extremely accurately. This commonly results in heat being lost through the structure.
Mineral wool
Mineral wool is a lower grade than PIR board, but it has a good fire resistance and it’s a lot cheaper than more thermally efficient alternatives.
Phenolic board
Phenolic board offers the highest thermal performance over PIR board or mineral wool. However, this benefit comes with a substantial price tag to match therefore it’s not everyone’s preferred material, especially since a multifoil insulation is still needed alongside it to meet building regulations.
Multifoil insulation
Our TLX Gold 2-in-1 insulating breathable membrane is a welcomed addition to a roof build-up, particularly in older buildings, as it is lightweight and easy to install. It comes with a breathable membrane overlap flap with integrated tape, enabling you to join sections together with ease.
When insulating an old building, compromise is key. You want an insulation material to be as effective as possible whilst causing as little disturbance to the building as possible. This can seem an impossible task, especially when you’re grappling with building regulation requirements and the comfort factor against shallow rafters and restrictive head height. However, our TLX Gold multifoil insulation goes a long way to manage these challenges. Keep reading below to find out how…
- TLX Gold can be used simply draped over the top of the rafters, meaning no change in roof height is necessary
- TLX Gold makes use of the layer of static air underneath it – The underside of TLX Gold is a shiny, breathable surface that reflects heat. This limits the amount of additional insulation required to achieve building regulations. Since it is breathable, it can manage condensation risk by allowing water vapour to travel through the multifoil, so none is trapped within the roof space
- TLX Gold is easy to install – It doesn’t require cutting or fitting to size. Simply join sections together by the aid of integrated tape on the overlap flap
- TLX Gold is BBA approved, filing the yards of builder’s merchants nationwide
TLX Gold performance:
TLX Gold multifoil insulation can reduce heat loss by up to 85%. An uninsulated roof has a U value of 3.67w/m2, and with the simple addition of TLX Gold, based on 75mm rafters, it achieves a 0.69w/m2k U value.
How to meet building regulations:
TLX Gold draped solution:
Drape TLX Gold multifoil insulation over a 185mm deep rafter and add 125mm of PIR board in-between.
Taut and counter-battened solution:
Secure TLX Gold multifoil insulation over the top of a 165mm rafter with counter-battens, then add 125mm of PIR board in-between.
Check out our Approved Solutions guide for a range of pre-calculated solutions. If you require a tailored calculation, our team of product scientists are on hand to help.
