Summary

Timber is the material most customers picture when they say "cladding" — the warm, natural look that composite and fibre cement products are explicitly designed to imitate. It's also the material most likely to be mis-priced, because the boards themselves look like the main cost when in fact the ventilated cavity, membrane, batten sub-structure and fixing specification are what determine whether the job survives its first decade. Timber cladding fitted direct to a solid wall with no airspace behind it, or fixed with galvanised screws on cedar, looks identical to a correctly detailed job on the day it's finished and starts failing — cupping, staining, rot at the base — within two or three winters.

This guide sits alongside the general material comparison in external wall cladding pricing guide and provides the timber-specific deep dive: profile types, species and treatment class selection, the fixing regime that prevents staining and corrosion, weathering behaviour (the number one source of "is this a fault?" callbacks), and a worked pricing example. For composite and brick-slip alternatives to timber, see composite cladding installation pricing guide and brick slip cladding pricing guide; for the render finish alternative, see external render pricing guide.

Timber cladding also carries a fire-safety dimension that isn't relevant to render: it's a combustible material, generally acceptable and widely used on ordinary houses under Building Regulations Part B, but the permitted proportion reduces the closer the wall sits to a relevant boundary, and the rules change entirely on taller or multi-occupancy buildings — covered in the fire section below and in more depth at cladding fire safety.

Key Facts

Quick Reference Table

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Species/Product £/m² Installed Finish Behaviour Maintenance Cycle Typical Lifespan
Treated softwood (painted/stained) £70–£110 Holds solid colour if maintained Re-coat every 3–5 years 25–35 years (maintained)
Treated softwood (left to weather) £70–£100 Weathers grey, less even than cedar None required 20–30 years
Cedar (unfinished, silvers naturally) £100–£150 Silvers evenly to grey patina over 1–2 years None required 30–50+ years
Cedar (oiled, retains tone) £110–£160 Retains warm tone if maintained Re-oil every 1–3 years 30–50+ years
Larch (unfinished) £100–£150 Similar weathering to cedar, slightly harder wearing None required 30–45 years
Accoya £130–£190 Can be left unfinished or coated; very stable Minimal 40–50+ years (manufacturer claim)
Elevation Size Treated Softwood Cedar/Larch Accoya
Small (20m²) £1,400–£2,400 £2,000–£3,200 £2,600–£3,800
Medium (40m²) £2,800–£4,800 £4,000–£6,400 £5,200–£7,600
Large elevation/full house (100m²) £7,000–£12,000 £10,000–£16,000 £13,000–£19,000

Detailed Guidance

The substructure, not the boards, is what you're pricing

Timber cladding is a layered build-up and the boards are the last and cheapest-per-hour part of the job:

  1. Substrate check and prep — wall inspected for defects, loose render removed, surface stabilised. On a new-build timber-frame wall this is minimal; on an existing solid wall being re-clad it can be a significant prep phase.
  2. Insulation (optional) — if the job is combined with a thermal upgrade, insulation boards go on first, similar to the render insulation systems build-up.
  3. Breather membrane — fixed over the wall or insulation, laps taped, to BS EN 13859-1.
  4. Battens and counter-battens — vertical battens for horizontal boards (or vice versa), forming the ventilated cavity; counter-battens where insulation sits behind. This layer is where most of the setting-out precision lives — battens must be plumb, level and correctly spaced for the board profile's fixing centres.
  5. Cladding boards — fixed with the correct stainless fixings, gapped for movement, starting from a level, plumb setting-out line (usually a level datum line struck around the whole elevation before the first board goes up).
  6. Trims and detailing — corner trims (external corner boards or metal trim), cill/head details at openings, base ventilation strip with insect mesh, top ventilation at the eaves.

A quote that prices "boards + labour" without itemising battens, membrane, fixings and trims separately will under-price the job by a wide margin — the invisible layers commonly account for 35–45% of total material cost on a timber cladding job.

Profile selection and how it changes labour time

Species selection — matching durability to budget and expectation

Treated softwood (tanalised/pressure-treated pine or spruce, featheredge or shiplap) is the affordable, most-requested option. It needs a maintenance cycle if painted or stained to hold colour — re-coat every 3–5 years — or can be left to weather to a grey tone, which is cheaper long-term but less even and predictable than cedar's weathering.

Cedar and larch cost more upfront but many customers specifically want the look of cedar silvering naturally, which needs no maintenance at all if left unfinished — this is a genuine selling point, not a compromise. Oiling periodically (every 1–3 years) retains the warm original tone instead, which is a maintenance commitment the customer needs to understand at quote stage.

Accoya (acetylated softwood) is a premium, dimensionally enhanced product with a manufacturer-claimed 50-year above-ground durability. It costs the most but requires the least ongoing intervention and holds its shape better than untreated softwood, reducing gapping and cupping issues over the cladding's life.

Whichever species is specified, confirm the timber's use class against BS 8417:2024 (preservation of wood, code of practice) for the specific exposure — full weather exposure but not ground contact is commonly Use Class 3, but the exact class depends on the species' natural durability rating and any preservative treatment applied. Under-specified timber (e.g. an interior-grade treatment on an exposed elevation) fails early no matter how well it's fitted.

Fixings — the detail customers never ask about but always complain about

Fixing spec is the single most common source of post-completion callbacks on timber cladding, and it's cheap to get right at quote stage:

Weathering — set expectations before the first course goes up

If a customer chooses cedar or larch left unfinished, the boards will silver to a grey patina over roughly 12–24 months, and the weathering is rarely perfectly even — north-facing or sheltered elevations weather slower and patchier than south-facing or exposed ones. This is normal behaviour, not a fault, but it is the single most common cause of a post-completion complaint call if it hasn't been explained clearly at quote stage. Put it in writing: "unfinished [species] cladding will change colour and weather unevenly over 12-24 months; this is expected and not a defect."

Fire safety on domestic timber cladding

For an ordinary house, timber cladding is combustible but widely used and generally acceptable under Building Regulations Part B — the constraint is the permitted proportion of combustible, unprotected external wall area relative to distance from a relevant boundary, not a blanket ban.

The picture is entirely different for taller and multi-occupancy buildings. Since Grenfell, Regulation 7(2) of the Building Regulations 2010 (introduced via the 2018 Approved Document B amendment, extended in December 2022 to certain residential buildings with balconies from 11m) bans combustible cladding materials — including timber — on relevant buildings 18m and above, sitting alongside the Building Safety Act 2022's higher-risk building regime. This isn't relevant to a standard house but must be flagged immediately on a converted block of flats, an HMO, or anything approaching the height thresholds. See cladding fire safety for the full A1/A2 classification detail.

Planning permission

Timber cladding changes the external appearance of the building, so it is not automatically permitted development — the same principle applies as for EWI (see external wall insulation pricing guide) and general cladding (see external wall cladding pricing guide). The principal (street-facing) elevation, conservation areas, and listed buildings are the most likely to require planning permission, and in a conservation area the choice of cladding may itself be restricted. Always check with the Local Planning Authority before quoting a visible material change. See permitted development householder and conservation areas.

Pricing example (35m² single-storey extension gable, cedar shiplap, unfinished, regional)

Item Cost
Breather membrane (35m²) £110
Treated battens + counter-battens £250
Stainless steel (A2) fixings £180
Cedar shiplap cladding, 22mm (35m²) £4,025
Corner trims, cill details, insect mesh, base ventilation strip £260
Labour (2-person crew, 3.5 days) £1,750
Waste disposal £110
Margin 20% £1,337
Total £8,022

Frequently Asked Questions

How much does timber cladding cost per m² fitted?

Treated softwood runs £70–£120/m² installed; naturally durable species like cedar and larch run £100–£160/m²; premium Accoya runs £130–£190/m². These figures include the ventilated cavity build-up (membrane, battens, fixings) and detailing, not just the boards — the boards themselves are typically only 40–55% of the total material cost.

Do I need to finish (paint, stain or oil) timber cladding, or can I leave it bare?

Cedar and larch can be left completely unfinished and will silver naturally to a grey patina over 12–24 months — a legitimate and increasingly popular choice that requires no maintenance. Treated softwood can also be left unfinished but weathers less predictably and has a shorter unmaintained lifespan; most customers choose to stain or paint softwood to hold a solid colour, which then requires re-coating every 3–5 years. Explain both options and the maintenance implication at quote stage.

Why do galvanised fixings cause black streaks on cedar cladding?

Cedar (and oak) contain naturally high tannin levels, which react with the zinc coating on galvanised fixings and cause corrosion and black staining that streaks down the board from every fixing point. Stainless steel (A2 minimum) doesn't react the same way and should be specified as standard on any naturally durable species, not offered as a chargeable upgrade.

Why does timber cladding need a ventilated cavity behind it if the boards are treated?

Treatment protects the timber from decay but doesn't stop moisture getting behind the boards through joints, end grain or driving rain. A minimum 25mm ventilated cavity, open at the base and top with insect mesh, lets any moisture that does get through dry out rather than sit trapped against the wall or the back of the boards. Fixing boards direct to a solid wall with no airspace is the single most common cause of premature timber cladding failure — cupping, staining and rot from the back, invisible until the damage is advanced.

Is timber cladding a fire risk on a normal house?

For an ordinary domestic house, no more than any other combustible material used sensibly — timber cladding is widely used and generally acceptable under Building Regulations Part B, though the permitted amount of combustible material reduces the closer the wall is to a relevant boundary. The rules change sharply for taller or multi-occupancy buildings, where Regulation 7(2) of the Building Regulations 2010 bans combustible cladding materials on buildings 18m and above (11m in some cases for residential buildings with balconies). Always confirm the building's height and occupancy classification before assuming standard domestic rules apply.

Regulations & Standards