🏗️ High-Density Slabs & Commercial Supply

Looking for Rockwool RW3, RW4, or RW5?
We specialize in supplying high-density acoustic and thermal slabs for specialized projects. Whether you need standard soundproofing or specific fire-rated insulation, we carry the full range.

RW3 (60kg/m³): Ideal for high-performance acoustic partitions.

RW4 (80kg/m³): Heavy-duty thermal and sound insulation.

RW5 (100kg/m³): Maximum density for industrial and fire-stop applications.

Don’t pay retail for bulk orders. Contact our dedicated sales team today for the best trade prices and live lead times on full-pallet quantities.

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Google Reviews ⭐ ⭐ ⭐ ⭐ ⭐

Our clients are repeat customers.

David Robinson

Goods supplied at a very good price. Delivery ahead of time and driver helped stow the boards. Some slight damage from the retaining straps, but nothing that won't cover easily. Would recommend as they seem to be able to get anything.

Shelley Cafer

Amazing customer service received on my first order with Next Day Insulation. Prices were very competitive too and all items were in stock and delivered quickly. I would definitely recommend and will be using them again in the near future. Thanks to Chris for all his help.

MiU Designs

Great customer service and delivered on time to a date that suited our onsite needs. I have used several times for numerous items and will use again! Highly recommend

Mark Jones

Great company to deal with and quick delivery,
What more could you ask for.

Read more reviews here

Why us?

Insulation Supplies for Hertfordshire

Hertfordshire is a short run from our Wembley base, and its housing is more varied than people expect. Stevenage, Hemel Hempstead and Welwyn Garden City grew as planned towns, so there's a large stock of post-war homes. Around them are period houses in St Albans, Hitchin and Harpenden, and a steady stream of new estates and business parks.

Post-war and new-town housing

Many post-war homes have narrow or partly filled cavities, and some were built using non-traditional methods. Where internal space is precious, external wall insulation lets you upgrade from outside. We supply EPS wall insulation together with render systems such as KLEiB and K-Rend. Check with building control, and with planning or your freeholder where relevant, before changing a façade.

Period homes in St Albans and the market towns

Older solid-walled houses are usually upgraded from the inside with insulated plasterboard, plus loft top-ups with loft roll. Conservation areas are common in these towns, which is another reason to work on the inside.

New builds and commercial units

For housebuilders and fit-out contractors, we supply cavity boards, floor insulation, MF ceilings and metal stud in pallet quantities.

Delivery and collection in Hertfordshire

We deliver to Watford, St Albans, Stevenage, Hemel Hempstead, Welwyn Garden City and across the county. Deliveries are kerbside with crane offload. Check stock before 10am for next-day options; standard delivery is 2–3 working days. If you'd rather pick up, collection from our depot is available by appointment.

Hertfordshire FAQs

Is external wall insulation worth it on a post-war house?

It can be, where cavity fill isn't possible or you don't want to lose room space. It's a bigger job, so talk to us about the wall type and the system before ordering.

Can I collect instead of having a delivery?

Yes, by appointment. Call 0330 133 4833 to arrange a slot.

Do you deliver into London?

Yes. See our London page.

Related project guides

Next Day Delivery to you or your site

Minimum Order £350.00 ex. VAT

Contact us for orders below £350.00

Delivery cost £50

£350.00 - £599.00 ex.VAT

Free Delivery

Over £600.00 ex.VAT