There is no definitive answer to this question. All four of our EWI external wall insulation systems provide benefits to their customers, some more suited to the needs and requirements of the project than others. Our technical team is always on hand with expert advice to suggest the best solution. So which will they suggest to you?
The premier solution is Rockwool, a mineral wool composed of volcanic rock and compiled to form slabs in a similar way to that of candy floss. The standout feature of this product is its complete non-combustibility, having achieved a Euroclass rating of A1. Rockwool can withstand temperatures of up to 1,000ºC, prevent the spread of fires, and not emit any toxic emissions. The acoustic insulation and dual density composition are further benefits to an already high performance system. Rockwool is also breathable! In turn, this allows trapped moisture in the existing wall to pass through the insulation and dissipate into the atmosphere, assuming a breathable Silicone render is used.
Kingspan Kooltherm K5 offers a highly effective and space-saving solution. The rigid phenolic core of the K5, bracketed by a glass tissue board, offers excellent thermal capabilities. Space saving features of the K5 make it the ideal choice for narrow passageways and alleys. The high compressive strength also ensures that any risk of mechanical compression and impact is minimised. External wall insulation as a rule reduces the households carbon footprint, with K5 boards also having an ozone depletion potential of zero.
EPS is the most popular external wall insulation, offering great value for money and still providing excellent thermal performance. The whole system is extremely lightweight, meaning that the cost for installation materials is far lower than Rockwool or K5. EPS has been designed specifically to be applied onto masonry or timber-backed walls using adhesive and mechanical fixings. They can also be installed in the cavity void if the property is being insulated using cavity wall insulation.
XPS or extruded polystyrene board is a high-density board that can be used for various applications on buildings, including DPC insulation, extending concrete window sills or providing insulation backing where EPS is not suitable to use. Being compact and robust means that XPS is easy to store and reduces the risk of water penetration.
You can review the product’s properties in our handy comparison table!
|Composition||Dual density mineral wool||Phenolic||expanded polystyrene, graphite||extruded polystyrene, silver boards|
|Water vapour resistivity||1.2% water absorption||300MN.s/g.m||145-238MN.s/g.m|
|Compressive strength||10 kPa||120kPa||70kPa||130kPa|
Contact our technical team on 0204 5719697 today for the best EWI solution! They will happily advise on how to lower your energy bills.