External Wall Insulation · Hertfordshire

External wall insulation in Hertfordshire

Just beyond London's northern edge, Hertfordshire has a lot of bungalows and detached houses with render that was put straight onto the wall decades ago. This page follows one of our Hertfordshire jobs, a bungalow where the old render had failed, from the first boards to the finished house.

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When old render lets go

Render applied directly to brick or block holds on for a long time, then starts to lose its bond. It sounds hollow when you tap it, cracks along the base of the wall and eventually comes away in sheets, as it did here below the window.

Patching that kind of failure rarely lasts, because the render round the patch is usually on its way too. On this bungalow the owners chose to insulate the walls at the same time as renewing the finish, since the preparation and access were needed either way.

Old render coming away from a bungalow wall below a window, with insulation boards fixed along the base — The old render failing below a window. The first insulation boards are already going on along the base of the wall.

Boards round the bays

The insulation boards are bonded and mechanically fixed across every wall, with the joints staggered. Bungalows often have curved or angled bays, and each face of the bay is cut and fitted separately so the finished shape stays true.

Downpipes, satellite brackets and meters are taken off or extended so the new, thicker wall runs cleanly behind them.

Grey insulation boards fixed round an angled bay window on a Hertfordshire bungalow — The bay fully boarded and fixed, ready for the mesh and base coat.

The finished front

After the reinforced base coat, the whole bungalow was finished in a pale yellow through-coloured render, carried round both bays and down to a neat base detail above the paving.

Hertfordshire bungalow finished in pale yellow render over external wall insulation, with two curved bays — The front of the bungalow finished: external wall insulation under a new render, round both bays.

One finish all the way round

The same system runs round the sides and back, so the house is insulated and weatherproofed on every wall rather than just the one you see from the road. The brick extension was left as it was, by the owners' choice.

Rear of the same Hertfordshire bungalow finished in pale yellow render, with a conservatory and a brick extension — The back of the same bungalow, rendered to match the front.

How a job runs

A surveyor visits, looks at the whole elevation and checks the wall build-up, damp risks, access and the planning position for your address. You get an itemised written quote that separates preparation, the system proposed, detailing around windows and sills, and scaffolding. On site the preparation is done first and properly, each coat is given its curing time, and the job ends with inspection, sign-off and warranty paperwork.

Hertfordshire questions

Which parts of Hertfordshire do you cover?

The south of the county, close to London: Potters Bar, Borehamwood, Cheshunt, Broxbourne, Hoddesdon, Watford, Bushey, St Albans and Hatfield. Send your postcode and we will confirm.

Can you insulate a bungalow?

Often, yes. Bungalows have a lot of exposed wall for their size, and many have render that has started to fail. We check the wall, the base detail and the eaves at survey before recommending a system.

My render is only failing in places. Do I need the whole house done?

Not always. If the damage is contained and the rest sounds solid, a repair can make sense. If large areas sound hollow or it has been patched before, a fuller approach usually lasts longer. We tap-test the walls and explain what we find.

Do I need planning permission?

Many houses can have external insulation without an application, but it depends on the property and the area. We check the planning position for your address at survey.

Book your free Hertfordshire survey

One short form, or a WhatsApp message with a few photos and your postcode. A real surveyor takes it from there.

Request a free wall check Take the 2-minute assessment