garage roof replacement cost

Jibber123

We have a large a garage approximately 4.5m wide by 8m long that has a felted pitched roof. It has had several temporary repairs over the past 10 years or so, but when I was in there the other day clearing out I've noticed a lot of root in the bottom of a couple more of the roof rafters several have been replaced the felt is also on its last legs and we've been told the 2x3 rafters are very small for such a wide span. Hence i'm looking at getting it replaced from the wall plates up. I've had 3 quotes from builders 2 local and 1 nationwide company the quotes are for all for complete replacement of time roof structure from wall plates upwards, concrete tiled roof and boarded out loft for storage. The quotes are £14,000, £12,500 & £15,995 and they also seem to say it will take 2 or 3 guys about 2 or 3 days to complete. Which seem a little on the high side. I've done a couple of smaller roofs in the past and I just don't have the time currently. I've worked out the timber costs for 8x2 joists and 6x2 rafters which is the size recommended in the UK timber span tables, plus chipboard loft floor, tile battens, noggins and ridge board and it come to £1500 the underfelt, and odds and sods nails and hardware comes to about £300 and tiles just over £1000. If you add a skip for £500 that makes about £3500, so the labour is over £10,000 for 3 guys for 3 days, are they all on £1000+ a day? Even if I factor in a structural engineer and planning permission, which I don't think I'll need as its as like for like replacement, something defiantly seems a miss. have I just been unlucky and got 3 builders who don't want the job and have put high quotes in, or are these quotes about right?

Albermarle

I know a family member had a standard sized garage with a flat roof, with rotting/insufficient roof timbers.

They had a new timber roof structure and a GRP roof covering. I think it cost nearly £10K .

ladruid

You’re looking at the job purely as materials + a few days of labour, but construction pricing doesn’t work like that. A company isn’t just charging for the time on site, they’re charging for risk, liability, overhead, and the fact they’re responsible for the structure once it’s built.

A few things missing from your calculation:

• Scaffolding - often £1,000–£1,800 depending on access
• Insurance + liability - structural roof work carries long‑term legal responsibility
• Admin, estimators, transport, tools, waste handling
• IBG / warranty schemes
• Building control involvement (usually required for a full structural replacement)
• Flashing, pointing, and tie‑ins if the garage is attached

And the part most people don’t realise: Builders price based on workload. If they’re stacked with work, they’ll price high because they don’t need the job. If things are quiet, they’ll price competitively just to keep the team busy.

So yes, your material estimate is maybe right, but the quotes aren’t just for materials and three days of labour. They’re for the whole package of risk, overhead, and responsibility that comes with replacing a roof structure.

The numbers you’ve been given aren’t unusual for companies, especially if they’re busy. I would advise getting a couple more quotes just to give yourself peice of mind.

Jibber123

Its a fully detached garage so ne flashing, i did include £500 for a skip and i will keep any waste timber for the log burner. I assumed they will work from bandstands as its only a single story roof around 2.1m to gutter height. I understand the companies have overheads. I've been a self employed trade person for a few years. I provided all my own tools and liability insurance while on the customers property. I understand you don't get sick pay holiday pay pensions etc. but all this considered I still only charged £25 an hour. I tried putting my prices up to make things work and I lost most of my jobs hence I went back to being employed. Maybe its just the wrong time of year to be getting roofing quotes and they are all busy and don't want the work.

tetrarch

Is it a single pitch (pent) roof?

If so then I would recommend EPDM rubber over felt. In my experience roofers recommend felt because it is what they do. Felt roofs are only good for 15 years so they guarantee future work

The EPDM itself is guaranteed for 40-50 years - the only problem is finding a fitter. It is possible as a DIY job. The roof I fitted in 2003 is still going strong

Regards

Tet