DIY GUIDE · HOME REPAIRS & HANDYMAN · CHECKED OCTOBER 2026
How to repair a garden shed yourself
A weekend. £60–£150 in felt, timber, fixings and treatment for a typical shed.
Re-felt the roof, replace rotten boards, rehang the door and treat the timber — and leave old cement-sheet roofs alone.
- Every step, start to finish
- Checked October 2026 — sources at the end
- Honest about when to call a pro
FIRST, THE HONEST ANSWER
Do it yourself, or get a repairer?
Do it yourself if…
- The shed is timber with a felted roof you can reach from a ladder at the eaves
- The rot is in individual boards, not the whole frame
- The base is sound or can be propped level
- You can pick a dry spell of a couple of days
Get a pro if…
- The roof is made of corrugated cement sheets — on an older shed these may contain asbestos
- The frame, floor bearers or the base itself have rotted or sunk
- The shed is large or two-storey, or the roof is beyond reach from a ladder
- Electricity runs to the shed and the cable or fittings are damaged
Safety first
- Work from a ladder, not on the shed roof. HSE's rules for leaning ladders include the 1-in-4 angle, not working off the top three rungs, and keeping your belt buckle within the stiles.
- Treat any old grey corrugated cement roof as possibly containing asbestos. HSE says asbestos was used in buildings until it was banned in 1999; do not drill, break, cut or clean it, and get advice.
- Old felt, nails and rotten boards are sharp. Wear gloves and glasses, and clear nails from the ground as you go.
- If the shed has an electricity supply, isolate it before working near the cable or fittings, and leave any wiring repairs to an electrician.
- Lift heavy rolls and boards with care; a roll of felt is awkward on a ladder, so pass it up rather than carry it.
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Shed felt | Rolls, commonly 10 × 1 m | Roof area plus overlaps and overhangs |
| Galvanised clout nails | Short, broad-headed | A box of 500 g covers a small roof |
| Felt adhesive | For the overlaps | A litre for a small shed |
| Shed treatment | 6 m² per litre on rough-sawn timber, one maker's figure | Wall area ÷ coverage |
| Replacement cladding and hinges | Matching profile; heavy tee hinges for the door | As needed |
How much felt and treatment
Felt: for each roof slope, the length of the slope plus the overhang at the eaves, times the width of the roof plus the overhangs at the gables — then add the overlaps between sheets and a ridge strip. An apex shed with two slopes of 1.2 m by 2.4 m long, plus overhangs and overlaps, needs about 8 m² of felt, so one 10 m roll. Treatment: the wall area of the four walls divided by the coverage. Walls totalling 18 m² at 6 m² per litre need 3 litres for one coat.
Add a margin for the ridge, the overlaps and a mistake; a short sheet in the middle of a roof is the worst outcome.
Standard shed felt is a bitumen sheet with a mineral finish, sold in rolls, commonly 10 m by 1 m. Heavier, polyester-reinforced grades last longer and tear less when you nail them. Shed felt is for sheds and small outbuildings; a garage or a habitable room needs a proper roofing system.
Use short galvanised clout nails, which have broad heads and will not rust through the felt. The felt maker's fixing guidance on one stockist's listing calls for overlaps of 75 mm, nailed at 50 mm intervals, and the top edge nailed at 500 mm centres. A felt adhesive on the overlaps keeps wind from lifting them.
Most sheds are rough-sawn softwood, which takes a pigmented water-based treatment. One maker's shed treatment covers 6 m² per litre in one coat, is rainproof in an hour, and needs a day above 10°C with no rain forecast. Smooth planed timber, like a door or a window frame, wants a different product made for it.
Match the cladding profile — shiplap, tongue and groove or overlap — and its thickness, and buy treated timber where you can. A mismatched profile lets water in at the joint. Take an offcut of the old board to the timber merchant to match it.
Exterior wood filler is for small, local soft spots that you have cut back to sound wood. One maker's multi-purpose wood filler is dry in two hours and can be sanded, screwed and painted. Anything larger than a patch, or anything structural, gets new timber.
THE PART THAT DECIDES THE FINISH
Before you start — by what the shed needs
Find the problem below. Each card is the check and the prep before you start work on it.
Leaking felt roof
Drips inside, stained roof boards, felt split or lifting.
- Look inside in daylight for light through the boards and dark, soft patches
- Press the roof boards from inside with a screwdriver; soft boards need replacing before new felt
- Plan to strip the old felt completely, not to lay over it
- Check the weather for two dry days
An old cement-sheet roof
Grey corrugated sheets, often on sheds built before 2000.
- Do not drill, cut, break, sand or jet-wash the sheets
- Do not stand or lean a ladder on them; cement sheets are fragile
- HSE treats anything built since 2000 as unlikely to hold asbestos, so an older shed may
- Leave it in place and get advice before any work
Rotten cladding boards
Soft, dark, crumbly boards, usually low down.
- Probe each suspect board with a screwdriver to find the extent of the rot
- Check the frame behind; a rotten upright means a bigger job
- Look at why it rotted — soil against the wall, a dripping roof edge, a blocked gutter
- Measure and match the board profile before you cut anything out
Sagging or sticking door
The door drops, drags on the floor, or will not latch.
- Check the hinge screws for looseness and the hinge for bending
- Check the frame is square by measuring its diagonals
- Look for a missing diagonal brace on a ledged door; that is what stops the sag
- Check whether the base has sunk at the door corner
Weathered, grey timber
Sound wood that has lost its colour and protection.
- Brush off dirt, cobwebs and loose flaking treatment
- Wash off green algae and let the wood dry thoroughly
- Check the forecast for a day above 10°C and dry
- Cover plants and paving below before you start
Damp floor or base
Spongy floor, water pooling round the base.
- Clear soil and leaves away from the bottom of the walls
- Check the bearers under the floor where you can reach them
- Check the base is level and does not hold water
- A sunken or flooded base needs fixing before any other repair
THE JOB
How to repair a shed, in order
Survey and set up
30 minEmpty the shed, or move everything to the middle under a sheet. Look at it inside and out in daylight and work through the cases above to list what it needs. Check whether the roof is felt or old cement sheet; if it is cement sheet, do not touch it and go no further with the roof. Set the ladder up at the eaves on firm, level ground, at the angle HSE gives for leaning ladders.
- Do the roof first, the walls and door second, the treatment last
- Check for wasps and birds' nests before you start pulling boards
- Lay a sheet on the ground to catch old nails
Mistake to avoid: Starting with the treatment because it is the easy part. Water from the leaking roof then runs down your fresh finish.
Strip the old felt
1 hrFrom the ladder, lift the edges of the old felt with the claw hammer and pry bar and pull it off in strips, along with the battens at the edges if there are any. Pull or hammer flat every old nail. Sweep the roof boards clean. Look at the boards in daylight: any that are soft, cracked or split are replaced now, before new felt goes on.
- Work from the ladder at the eaves; avoid putting your weight on the roof boards
- Bag the old felt as you go; it is heavy and sharp-edged
- Leave a dry roof uncovered for a short time only; plan to finish the same day
Mistake to avoid: Laying new felt over old. The old splits and nail holes trap water underneath and the boards keep rotting.
Replace soft roof boards
1 hrCut out any soft roof board between the rafters with a handsaw, and fit a new board of the same thickness, screwed to the rafters. Where the tongue of a tongued board will not go in, plane it off and use a timber support under the joint. Make sure the new board sits flush with its neighbours; a step under the felt becomes a split later.
- Treat the cut ends of new timber with preservative before fixing
- Use exterior screws long enough to bite well into the rafters
- Check from inside that no screw point has come through where a head will knock it
Mistake to avoid: Leaving a soft board because the felt will cover it. The first heavy snow or a ladder rung goes straight through it.
Felt the roof with proper overlaps
2 hrCut the first sheet for the lower edge of one slope, with an overhang at the eaves and at each gable. Lay it, then nail the top edge at the spacing the felt maker gives and work down, keeping it flat and taut. Lay the next sheet above, overlapping the first by the amount the maker gives — 75 mm, in one maker's instructions — with felt adhesive on the overlap, and nail through the overlap at close spacing. Repeat on the other slope, then fit a ridge strip over the apex lapping down both sides.
- Work on a mild day; cold felt cracks when folded, hot felt tears under nails
- Fold the felt neatly round the gable edges and nail on the side, not the top
- Fit fascia or edge battens over the folded edges to stop wind lifting them
Mistake to avoid: Nailing too few nails, too far apart. The wind lifts the edges in the first gale, and water gets under at once.
Cut out and replace rotten cladding
1 hrFind the extent of the rot with a screwdriver and mark a cut line on sound wood either side, over the centres of the frame uprights where you can. Cut the board along the lines with a handsaw, prise the piece out and pull its nails. Cut a new board of the same profile to fit, treat its cut ends, slot it in with its tongue or overlap matching the boards above and below, and nail or screw it to the uprights.
- Cut on an upright so both ends of the new board have something to fix to
- Fit the lowest boards last, after clearing soil away from the wall
- Treat behind the new board while you can reach
Mistake to avoid: Filling a large rotten area with wood filler. Filler bridges a patch, not a board, and the rot behind it carries on.
Rehang or brace the door
1 hrWith a helper holding the door, take out the hinge screws. If the holes are stripped, glue in timber dowels and redrill. On a ledged door with no diagonal brace, fit one running up from the bottom hinge side to the top latch side, which stops it dropping. Refit the door on heavier tee hinges if the old ones have bent, with longer screws into the frame. Check it swings clear and the latch meets.
- The brace must run from low on the hinge side to high on the latch side; the other way round does nothing
- Pack the door up on wedges to the right height before fixing the hinges
- Fit a hasp and staple with security screws or coach bolts
Mistake to avoid: Fitting the brace the wrong way. It hangs off the latch side instead of holding it up, and the door sags just the same.
Fill small soft spots
30 minWhere rot is shallow and local — the end of a board, a window sill corner — dig out all the soft wood back to sound timber, let it dry, then press exterior wood filler in, slightly proud. Once it has hardened, for the time on the pack, sand it flush and treat it with the rest of the shed.
- Dig out all the soft wood; filler over rot traps it
- Shape the filler so water runs off, not into the joint
- Prime filled sills before the treatment if the pack says so
Mistake to avoid: Filling over damp wood. The filler does not bond and pops out in the first frost.
Clean and treat the timber
3 hrOn a dry day above the temperature the tin gives — 10°C for one maker's shed treatment — brush the walls down to remove dirt and loose material. Stir the treatment and apply it generously with a wide brush along the boards, working from the top down so drips land on bare wood. Do the end grain and the bottom edges twice; that is where water gets in. Leave it to dry, and judge after the first coat whether weathered wood needs a second.
- Brush into the overlaps and joints, not just the faces
- Keep a wet edge along each board to avoid lap marks
- Cover plants, paving and the car before you start
Mistake to avoid: Treating the shed on a cold, damp day. The treatment does not soak in, and the first shower washes it off.
Check the base and tidy
30 minClear soil, leaves and plants from the bottom of the walls so they stay dry, and check the gutters if the shed has any. Look at the base: if water pools under or round the shed, clear a drainage gap or improve the falls. Put the contents back on shelves and off the floor where you can, so air can move round them.
- Keep a gap between the shed and fences, walls or hedges so the walls dry
- Raise the floor off a damp base on treated bearers if it sits directly on soil
- Ventilate the shed on dry days
Mistake to avoid: Piling soil, compost or logs against the walls. They hold water against the bottom boards and rot them in a season or two.
The mistakes that shorten a shed's life
- Felting over old felt
- Too few nails and too little overlap
- Working on an old cement-sheet roof
- Treating the walls in cold or damp weather
- Leaving soil and plants against the bottom boards
Stop here and get a shed repairer
- The roof is cement sheet or may contain asbestos
- The frame, bearers or base have rotted or sunk
- The shed is too big to reach from a ladder, or has two storeys
- Electricity to the shed is damaged
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| Shed roof leaking after re-felting | Overlaps too short, nails too sparse, or the edges not folded and fixed. Lift the leaking overlap, add felt adhesive and nails at close spacing, and fix edge battens. |
| Shed felt lifting in the wind | Edges not nailed or battened. Glue and nail the edges and fit timber battens over the folded felt at the gables and eaves. |
| Shed door dropping and dragging | Hinge screws pulled out, or no diagonal brace. Plug the holes, fit heavier hinges, and add a brace from the bottom hinge side to the top latch side. |
| Soft rotten boards at the bottom | Soil, plants or a wet base against the walls. Replace the boards, clear a gap at the base and keep it clear. |
| Treatment washed off | Applied in damp or cold weather, or rain came too soon. Let the wood dry and reapply on a warm, dry day. |
| Condensation dripping inside | No ventilation under a felted roof. Fit small vents high in the gables and keep the door open on dry days. |
| Green algae on the walls | Damp, shaded timber. Brush and wash it off, let the wood dry, treat it, and cut back plants that keep it shaded. |
| Floor spongy underfoot | Rotten floor boards or bearers. Lift the boards to check the bearers; rotten bearers mean lifting the shed, which is a two-person or professional job. |
WHAT YOU SAVE
What it costs to do it yourself
| Shed felt, 10 × 1 m roll | £32–£40 |
|---|---|
| Felt adhesive | £11–£23 |
| Galvanised clout nails | £4–£5 |
| Shed treatment, 5–9 L | £19–£25 |
| Hinges and hasp | £4–£11 |
| Total, a typical shed | £60–£150 |
| DIY total | £60–£150 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
A shed re-felt and treatment costs a fraction of a new shed; a repairer's price buys the work at height and the two-person jobs.
RATHER NOT?
Shed repairers near you, with prices shown
The ones who cover your area, nearest first, with one score from every review. No account needed to look.
Or post the job free and let them come to you.
Check the overlaps and edges before winter and re-glue anything lifting.
One maker's shed treatment lasts up to two years; re-coat when the colour fades or water stops beading.
Old felt, treated timber offcuts and rotten boards go to the household waste recycling centre; check your council's website, as some charge for DIY waste. Never burn treated timber or felt. Asbestos sheets must never go in a skip or a bin; your council will say how to arrange a licensed collection.
Wash water-based treatment out of brushes and sprayers straight away with water.
Repairing a garden shed: questions people ask
Strip the old felt, replace soft boards, then lay sheets from the eaves up with an overlap, nailing the edges and the overlaps closely and gluing the laps, with a ridge strip over the top. One felt maker's instructions give 75 mm overlaps nailed at 50 mm intervals.
No. Strip it, so you can see and replace soft boards and get a flat surface for the new felt.
Plug the stripped hinge holes, fit stronger hinges, and add a diagonal brace from low on the hinge side to high on the latch side.
Grey corrugated cement sheets on a shed built before 2000 may contain asbestos. Do not disturb them; leave them in place and get advice.
Dry, with no rain forecast, and warm enough for the product — one maker says above 10°C.
On the Locufy UK price guide shed repair costs £65–£450 per job, typically £250. A re-felt sits in the middle; a new floor or base at the top.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- Ronseal — One Coat Shed & Fence Protector: 6 m² per litre, rainproof in one hour, dry in four, above 10°C, up to two years
- Ronseal — how to repair rotten wood (wet rot signs; wood filler dry in two hours)
- IKO shed felt fixing instructions, as listed by a stockist: 75 mm overlaps, nails at 50 mm, top edge at 500 mm centres
- HSE — types of ladder and using them safely (leaning ladders, the 1-in-4 rule)
- HSE — introduction to asbestos (banned in 1999; buildings after 2000 unlikely to contain it)
- GOV.UK — dispose of household waste: DIY waste and the recycling centre
- Wickes — shed felt and felt adhesive, price check October 2026
- Wickes — clout nails, price check October 2026
- Wickes — shed treatment, price check October 2026
- Wickes — shed hasps, price check October 2026
- Wickes — tee hinges, price check October 2026
