Question 1

Does underfloor heating work with every floor covering?

Accepted Answer

No — the covering sits **between** the heat source and the room, so its **thermal resistance** directly determines how well the system performs, and some coverings simply throttle it.

**The number that governs everything.** Every floor covering has a thermal resistance, expressed as a **tog** or an **R-value**. The higher it is, the more the floor insulates rather than transmits. Most underfloor heating manufacturers specify a **maximum total resistance** for the covering and any underlay combined — commonly cited around 2.5 tog for the whole build-up, though it varies by system, so check the specific product.

Exceed it and two things happen: the room takes far longer to reach temperature, and the system must run hotter to compensate, which wastes energy and — with a heat pump — undermines its efficiency directly.

**Best performers:**

**Tile and stone.** Excellent conductivity and high thermal mass. This is the ideal pairing, and the reason underfloor heating and tiled bathrooms go together.

**Polished concrete and screed** finishes.

**Good, with conditions:**

**Engineered wood.** The standard choice for timber floors over underfloor heating, because its layered construction is far more dimensionally stable than solid timber. Keep it reasonably thin and follow the maximum surface temperature the manufacturer states.

**Vinyl and LVT**, provided they are rated for it — many are, and there is usually a temperature limit.

**Laminate**, if specifically rated, with a compatible underlay.

**Problematic:**

**Solid hardwood.** It moves with moisture and temperature, and repeated cycling causes gapping, cupping and cracking. Some species and installations work; many do not.

**Thick carpet with a thick underlay.** This is the classic failure. Carpet alone may be acceptable; **it is usually the underlay that breaks the budget**, and a low-tog underlay specifically made for underfloor heating is essential.

**Thick rugs on top** create local hot spots and reduce output — worth knowing before furnishing.

**Also check:** the maximum floor surface temperature, adhesive rated for heated floors, and running the system through a **commissioning cycle** before laying timber.

Question 2

How do I work out what size radiator I need?

Accepted Answer

By calculating the heat loss of the room, then choosing a radiator whose output matches or slightly exceeds it. Radiator output is quoted in BTU per hour or watts (1 watt ≈ 3.41 BTU/h). What

Question 3

What is a U-value, and is triple glazing worth it?

Accepted Answer

A U-value measures how quickly heat passes through a building element, in watts per square metre per kelvin (W/m²K). Lower is better — it is the opposite convention to insulation R-values, which is a

Question 4

How to choose energy-efficient windows?

Accepted Answer

Choosing energy-efficient windows involves considering frame materials, glazing options, Energy Star ratings, U-factors, SHGC, and air leakage ratings to enhance comfort and reduce energy costs.

Question 5

What are the pros and cons of different flooring types?

Accepted Answer

Understanding the pros and cons of different flooring types helps in making informed choices. Common options include hardwood, laminate, vinyl, tile, and carpet, each with unique benefits and drawbacks.

Question 6

Why is one room in my house always colder than the others?

Accepted Answer

Because heat loss and heat delivery are not distributed evenly around a house, and one room is usually losing more, receiving less, or both. Working through the possibilities in order saves a lot of

Question 7

Why does a heat pump need bigger radiators?

Accepted Answer

Because a heat pump produces water at a much lower temperature than a gas boiler, and a radiator's output depends heavily on how much hotter it is than the room. The temperature difference. A gas

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