The short answer. For an 8×6 shed, timber's lower upfront cost evaporates by Year 3 once you add base, treatment, and the first repair cycle. Steel breaks even around Year 3–4 and pulls ahead from there. For a 10×8, steel is cheaper in total cost from Year 1 in most cases: the purchase price gap is smaller and the maintenance saving is the same. If you're staying put for more than 4 years, steel wins on total spend for anything above 8×6.
The assumptions behind these numbers
All prices are 2026 Irish market rates, cross-referenced against Sheds Direct Ireland, Steeltech, Garden Sheds 4 Less, and Adman published pricing plus our own cost guide. The comparison uses a like-for-like scenario: a sheltered suburban garden (not Kerry coastal, not Dublin hillside), standard concrete-slab base, supplier delivery and erection included, no planning complications.
Treatment costs use Ronseal Fence Life Plus (the most widely available Irish option) at current Woodies/B&Q pricing. Repair costs are industry averages (a slate replaced on a timber roof, a corroded bolt on a steel frame), not worst-case scenarios. We're comparing a mid-tier timber (pressure-treated, not dip-treated) against a mid-tier galvanised steel, both from reputable Irish suppliers.
8×6 shed: year by year
The 8×6 is the most commonly purchased size in Ireland. It fits a standard suburban garden, stores a mower, two bikes and a season's worth of garden tools. Here's what it actually costs across five years in each material.
Year 0: Purchase + base + erection
Timber: €850 shed + €250 concrete slab base + €150 erection + €100 delivery. Steel: €1,200 shed + €250 concrete base + €200 erection + €100 delivery. Steel sheds are heavier and take longer to erect; some suppliers charge more. The base cost is identical: a concrete slab under either shed is non-negotiable if you want it to last.
Year 1: Initial treatment (timber) / nothing (steel)
A pressure-treated 8×6 should get its first coat of preservative in Year 1, before the factory treatment starts to fade. Two 5-litre tins of Ronseal Fence Life Plus (€32 each), plus a brush applicator. Some suppliers say Year 2 is fine. We'd do it in autumn of Year 1 to front-run the winter. Steel needs nothing: no treatment, no painting, no annual inspection beyond checking the door seal.
Year 2: Likely nothing either way
Year 2 is usually quiet for both materials if Year 1 treatment was done on time. Check the timber door frame for any early swelling or paint lift (common in Ireland's damp winters), reseat the door latch if needed. These are free if you have a screwdriver. Steel: check that no panel screws have worked loose after the first winter's thermal cycling. Five minutes.
Year 3: Re-treatment (timber) / minor check (steel)
Timber gets a second treatment coat: same cost as Year 1. Steel may need a touch-up of any scratched powder coating to prevent surface rust spreading under the finish: a small tin of matched paint (€15). This is optional but extends the life of the coating significantly in higher-humidity gardens.
Year 4: First small repairs emerge on timber
By Year 4, a mid-tier timber shed will typically show one or more minor issues: a warped door board, a soft spot on the floor, a loose felt strip on the roof. These are €40–€120 to fix depending on severity. We've used €80 as the average. Some sheds stay clean to Year 5; sheds in north-facing gardens or areas with poor drainage (pooling water against the base) often see issues sooner. Steel: nothing at this stage under normal conditions.
Year 5: Re-treatment + possible repair (timber) / nothing (steel)
Third treatment coat for timber (€65), plus a further minor repair allowance (€35: tightening floor boards, replacing a hinge, clearing a blocked drain channel). Steel: door seal replacement if it's showing brittleness after five winters (€20 for a generic neoprene strip, DIY fitting).
8×6 cumulative 5-year cost
| Year | Timber running total | Steel running total | Steel advantage |
|---|---|---|---|
| Year 0 | €1,350 | €1,750 | Timber −€400 |
| Year 1 | €1,415 | €1,750 | Timber −€335 |
| Year 2 | €1,415 | €1,750 | Timber −€335 |
| Year 3 | €1,480 | €1,765 | Timber −€285 |
| Year 4 | €1,560 | €1,765 | Timber −€205 |
| Year 5 total | €1,660 | €1,785 | Timber −€125 |
At five years, timber still holds a €125 advantage on an 8×6. But the gap has closed from €400 to €125 in five years: at that rate, steel breaks even around Year 7–8. And the Year 5 timber shed is starting to age; the steel shed has barely been touched.
10×8 shed: the calculus flips
The 10×8 is where most buyers who want to actually use the shed (workspace, bike storage, garden office ambitions) land. Here the material premium for steel is proportionally smaller, and the maintenance saving is identical. The five-year crossover moves to Year 1.
| Year | Timber 10×8 running total | Steel 10×8 running total | Steel advantage |
|---|---|---|---|
| Year 0 (purchase + base) | €2,200 | €2,350 | Timber −€150 |
| Year 1 (treatment) | €2,280 | €2,350 | Timber −€70 |
| Year 2 | €2,280 | €2,350 | Timber −€70 |
| Year 3 (re-treatment) | €2,360 | €2,365 | Steel +€5 ← crossover |
| Year 4 (repairs) | €2,460 | €2,365 | Steel +€95 |
| Year 5 total | €2,580 | €2,385 | Steel +€195 |
For a 10×8, steel breaks even at Year 3 and is €195 cheaper by Year 5. The purchase price gap at this size is only €150: a single treatment cycle wipes it out. Every year beyond Year 3, steel gets further ahead.
What these numbers leave out
This comparison doesn't include everything. A few factors that can push the numbers in either direction:
Things that make timber more expensive than modelled
- Atlantic exposure. A Kerry or Galway coastal site will see timber degradation 2–3× faster than a sheltered Dublin garden. Treatment frequency doubles; repair frequency doubles. In exposed western counties, the 5-year timber cost can be €400–€600 higher than the figures above.
- North-facing or poorly drained sites. A shed that stays damp between rains rots faster. If your shed sits against a north wall that never dries out, add 30–50% to Year 4–5 timber repair costs.
- Dip-treated, not pressure-treated. Some budget timber suppliers still sell dip-treated boards. These cost less upfront but typically need first treatment at Year 1 and show wear by Year 3. If you bought dip-treated, add one extra treatment cycle and move the first repair to Year 3.
Things that make steel more expensive than modelled
- Coastal salt spray. Steel powder coating degrades faster near the sea. Year 3 touch-up cost rises; Year 5 may require a full external respray (€150–€250 DIY). For coastal sites, galvanised steel with marine-grade coating is worth the premium over standard powder coat.
- Very large structures. A steel 12×10 or 14×10 garage shed can have panel replacement costs that timber doesn't: a dented or rusted panel is expensive to swap. Timber boards are cheap and DIY-replaceable.
- Cheap imported steel. Not all steel sheds are equal. Very low price-point steel from non-Irish importers often uses thinner gauge panels that dent easily and corrode faster. Steeltech and Adman are the benchmarks: their pricing reflects better gauge and warranty. Budget steel quoted at €600–€800 for a 10×8 is not the same product.
The resale and replacement question
Neither a timber nor a steel shed adds meaningful resale value to a property: Irish estate agents don't price outbuildings this way. But there's a replacement cost to consider at the end of the shed's life.
A well-maintained steel shed (Steeltech, Adman) can realistically last 25–30 years before the frame degrades to replacement point. A mid-tier pressure-treated timber shed in a sheltered Irish garden: 15–20 years with consistent treatment. A budget dip-treated timber shed: 10–12 years.
If you divide the Year 5 total cost by the expected lifespan in years, the annual cost of ownership comes out like this:
| Product | 5yr total cost (8×6) | Expected lifespan | Annual cost |
|---|---|---|---|
| Budget dip-treated timber | €1,500+ | 10–12 years | €125–€150/yr |
| Mid-tier pressure-treated timber | €1,660 | 15–20 years | €83–€110/yr |
| Mid-tier galvanised steel | €1,785 | 25–30 years | €60–€71/yr |
On an annual cost basis, mid-tier steel is 25–30% cheaper than pressure-treated timber over the full life of the product, even though it costs more to buy.
When to buy timber
You're renting, you're in the property for under 5 years, or you have a genuinely tight budget and a sheltered, well-drained east-coast garden. An 8×6 timber shed is the right call here: lower upfront cost, still has a 5-year cost advantage, and you can sell or disassemble it if you move. Also: if aesthetics matter and you want the shed to blend into a traditional garden, timber wins visually.
When to buy steel
You're staying put for 5+ years, you want anything over 8×6, you're in an Atlantic county, or you're storing anything valuable (bikes, tools, power equipment). Steel is cheaper on an annual cost basis from Year 5 onwards, it's more secure, and it asks nothing of you year to year. At 10×8 and above it's cheaper in total cost from Year 3. For most Irish buyers planning to stay in their house, steel is the rational choice.
How to get the right price
The purchase price is the biggest variable in this comparison. It can swing ±20% depending on which supplier you use and whether you negotiate. Adman's display-centre model means you can walk in and negotiate on the day; Steeltech's online model means you compare quotes against published prices. Garden Sheds 4 Less's free erection inclusion changes the Year 0 maths for timber.
The simplest way to pressure-test these numbers for your specific situation is to get three quotes. Our free multi-quote form puts your enquiry in front of up to three Irish suppliers in your county. They quote you directly with your specific size, material and county delivery cost included. No booking fee, no spam.
For the full materials trade-off (not just cost), read the buyer's guide. For what the quotes should include, read the cost guide.