Rate & Review
Kingspan Kooltherm K5 External Wall insulation Board (0.72m²)
SKU: KNG-K5-100
Reviews & Ratings
great K5 for tight sills & cuts clean, saved vital space. A premium product, but it really is quite pricey for a board.
absolute joke, paid premium but the k5 boards were damaged + warped insatntly. basecoat peeled off first rain. customer service completely MIA
Sorted the tight fit, brilliant insulation. The thickness saved loads of room!
K5's thermal perf is brill for tight spaces and meets U-values. Right solid but was tough to cut.
Top quality phenolic kit. U-value calc solid, kept the reveals tight. But the initial price is proper heavy for bulk jobs.
Proper job in tight spots. Made the place much warmer now.
pricey. Boards look cheap cos the facing colour is off.
Amazing perf. Slim K5. Took a day longer tho.
premium price for the K5 is totally out of sync with the effort. Needed WAY more anchors than the guides suggested just to feel secure; paid a bomb for a fixing schedule I'd use on a bulky PIR. Plus cutting this stuff is a nightmare mess. EWI-225 went on rough. Didn't feel "superior" for the headache it caused my lads on site.
Only thing that fit the reveals. Brill stuff.
K5 boards are mint. Proper space saver.
Rubbish order experience. Boards came damaged and slightly undersized. Every corner was chipped making waste awful. Bowing on installation means the render finish isn't true. Basecoat wasn't stocked, and tech support never called back. Total faff.
complete shambles on this one. Fixings weren't even included and support passed me around for an hour trying to get info. The pallet was soggy, edges crumbled unpacking it. Expensive and totally not worth the hassle.
Fantastic stuff! Sorted us right out on a tight EWI job.
This K5 board is a doddle to work with. It let us get a brilliant U-value on the external wall without eating up the narrow passage and saved crucial millimeters under the window sills. That's exactly why you pay the premium price, and it absolutely delivers. Cutting the boards was easy, proper clean cuts, and they stuck tight with the EWI-225 Basecoat straight away. Good peace of mind on the fire rating too (C-s2,d0). Delivery driver was spot on helping put the pallets right where they needed to be. Highly recommend this for performance and where space is tight. Can't fault it, to be fair.
Kingspan K5. Top bit of kit. Excellent thermal perf and genuinely space-saving as promised for narrow gaps. Delivery was fast and the driver helped with the heavy kit. It's definitely premium on the price front and instructions could be lcearer on the joint sealing. Good adhesion.
Best thin-line insulation used! The R-value in this pace is a lifesaver.
Average results. Paid premium cost for this K5 spec. Cutting the boards was too slow and a bit of a faff, keying felt difficult so that's why it was such a job
Thin profile, amazing insulation. Perfect for tight builds. Will buy again!
absolute joke service right then the boards are fine premium kit but the support is shocking i emailed technical support about moisture resistance weeks ago still nothing i need that answer so we can move the job forward and they ghosted me mate this isnt how you treat paying customers i might aswell have gone for the cheaper pir insulation total shambles. waiting a whole week for a simple technical detail when the K5 costs a bomb is ridiculous. DONT BUY THIS IF YOU EXPECT ANY SUPPORT.
Spot on K5. A doddle to cut and fix. Performance is brilliant and perfect for that narrow spot. Will buy again.
Proper job. Kingspan's slim phenolic board delivered fantastic thermal numbers in a dead tight area. Zero bulk needed. Excellent kit.
slimline K5 boards are perfect for difficult reveals, easily cut. Heat retention great
Pheolic rigid, thin render looks spot on.
Kooltherm K5 foam quality is sound. Thinnest board for that proper U-value performance. Brill.
For retrofit jobs where every milplimetre counts, this is top tier gear. K5 thermal spec is brilliant. No issues with EWI-225 bonding, went up solid.
K5 is brilliant. So much saved space!
Top K5 R-value. Bit dusty heavy handling required.
Good, solid stuff. Performance is spot on for tight spaces (dead slim build-up). Premium price feels steep vs PIR. Got the wrong fixings sent out too.
K5 thermal spec is brilliant for thin installs saves loads of space round sills. A bit pricey but the performance is there. Instructions need work, especially fix detail.
space-saver soerted the EWI. Expensive, mind.
Weak thermal output considering the high cost. Should have used a cheaprer alternative, mate.
This K5 is proper quality, kept the depth down & gave us a dead straight finish.
K5 - Premium Kit for Tight Spaces Mind the Dust.
The K5 insulation is top-notch. It solved my narrow passageway problem completely—standard PIR/EPS just wouldn't fit so this space saving phenolic core (0.022 W/mK!) was perfect for hitting the required thermal performance. Worth the extra money compared to bulk boards when you are really up against it for depth. The core feels incredibly robust and the 1200x600 size was sound for lugging onto the scaffolding.
Why not 5 stars? It's expensive compared to standard insulation and frankly I wish the fire rating was B for the price tag. Proper dusty stuff when cutting—you need decent respiratory kiddy and your saw blade will get hammered quick due to that dense core. We were short one board on the delivery which caused a follow-up call but CS sorted it quickly. Also I needed a few more mechanical fixings than the guideline suggested for my substrate. Solid product though, final result will be a brilliant, warm finish.
Worth the extra quid. Proper space saver mate.
Kingspan K5 EWI saved space vs Rockwool. Cracking thermal!
K5 is worth the high cost for the slim EWI stack up. Thermal is brill, but fixing lengths provided were always too short for the substrate.
feot cheap and flimsy, flexing loads. Not worth the money mate. Stick to XPS.
Slim board smashed the U-value. Sorted!
K5 profile fits a treat for tight windows.
Proper performance. Finally sorted the tricky wall runs with this K5 kit.
Right, had a tight run with a window sill that couldn’t be extended, total headache. We needed a seriously thin profile that could still hit the U-value target. That’s why I took a chance on this K5 phenolic gear; the thermal conductivity is miles better than my old insulation, honest. We absolutely nailed the performance spec without sacrificing external space, sorted that difficult insulation challenge spot on. This saved the lads serious hassle and we achieved noticeable comfort improvements quickly inside.
The phenolic core felt really solid, which helped massively with handling and installation being surprisingly straightforward. You just don't get that rigidity with other stuff. And this is key: the board edges fit together perfectly snugly, we didn't spend half the afternoon trying to pack gaps out before skimming, that’s time saved. The cutting was clean and kept square too.
The EWI Pro guide was exceptionally clear and helpful—got some excellent pre-sales advice on fixings specifically, which was a bonus. We successfully managed the whole project without needing intervention because the kit was so good. Used the EWI-225 basecoat and the thin coat render adhered *perfectly* to the surface. Looked proper professional when the whole external system was finished.
Even fire safety felt manageable; the Euroclass C rating provided adequate peace of mind. Delivery was sound too, much faster than initially expected and the boards arrived tidy and undamaged due to good packaging. Customer service was bang on with an order query; efficiency was top notch. While this isn’t the cheapest option, the price point offered great value for the premium performance achieved in those tight areas. Chuffed with this kit. It’s done the job.
K5 board nailed the U-value requirement in the tight gap. Space-saving hero and a solid bit of kit. Really happy.
Dead slim board. Massive thermal performance boost. Brill!
Slimline thermal results!
Spot on K5. Needed the slim board for a tight job and this worked good. Got the U-value we needed fast, saves loads of space. Sound rigidity too. Brill!
Worth every penny, that thin profile is spot on. Can't fault the U-value!
Proper thin board with zero issues. The EWI-225 mix grabs instantly, felt dead secure from the off. Right chuffed. Sorted!
great thermal spec for thinness. Pricey for C-class rating.
spot on thermal performance for those tight spots where thickness matters. Excellent lambda. Felt like a proper faff to cut cleanly mind you edges were delicate. Price is steep when covering a larger area.
i paid top money for this premium insulation for the u-value alone and the delivery was a joke. missing the esesntial ewi-225 basecoat entirely! whloe day wasted waiting on site 'cos i can't fit the obards without it. and for the price, seeing thm bow slightly after ONE brief pell of drizzle on site? terrible value and egven worse service. AVOID.
Proper K5 slab. Excellent U-Value with a clean finish. Saved loasd of room, spot on.