The Longevity of a Wooden Shed?

[DTR]

Afternoon All,

The title says it all really. I'm curious to know what the expected lifespan of the average shed is?

I've recently been contemplating the future of my workshop. It is a typical modern shed: bought in 2010, made from pressure treated 16mm t&g, regularly painted etc, mature trees sheltering the rear.... I'm in my thirties so I hope to have many years of workshopping ahead of me and a house-move isn't looking likely. How many years can I expect to get out of this shed? Is it worthy of investment (insulation etc) or do I need to focus on a more permanent structure?

As always, thank you for your opinions

 

[custard]

There are people on this forum with far more experience than me when it comes to this question, but I'd guess that with a felt covered roof the roofing material will start to fail after about ten years, and if it's not on a proper base then you'll start to see rot, again after about ten years. But looked at from the other end of the telescope, a decent shed standing on a proper base, and with the roofing material replaced when necessary, well that would likely outlast you!

 

[Racers]

I have a 25 year old shed given to me by may mother-in-law, it needed some rebuilding as it had knackered felt on it for 10 years, but its still going strong.
I did replace the roof timber 5 years ago with ply and 15 year felt.

Pete

 

[AJB Temple]

We have 8 sheds, one plastic. Six of them were here when we bought the house and they are all typical wooden garden sheds from various suppliers. They are about 10 years old and all of the wooden ones are knackered.

I am replacing them with much more substantial buildings. We have put up a 16ft by 10ft potting shed (actually sold as a workshop by a shed supplier) on a proper concrete slab with drainage, raised floor, cedar shingle roof etc, sturdily constructed with timberfix fittings and I expect this to still be there in 50 years. Do the job right with proper maintenance and protection and things will last very well.

 

[Cheshirechappie]

The cheap, basic wooden garden sheds can disintegrate remarkably quickly. Next door's put one up about eight years ago. The roof fell in after five years.

On the other hand, the shed in the garden behind my parents' house has been there for forty years that I know of, without any maintenance whatever, and it's still going strong.

Luck of the draw, I think!

 

[SteveF]

I built my shed with cedar and a edpm roof
hopefully i will never need to repair it

Steve

 

[Freddyjersey2016]

Keys to long life of any wooden structure IMHO:
1. Keep the bottom of the walls dry by getting it off the ground and incorporating damp-proof course under any wooden bearers - and accept that wooden bearers might have to be replaced every 10 years anyway
2. Replace the felt roof before it fails -- that way the water will not have got into the wooden structure and started to rot it - box profile steel is not that expensive on a big shed and not much harder to fit than a felt roof
3. Consider upgrading some of the internal studs if they are less than 45x45 - they dont have much meat in them
4. Consider installing some diagonal bracing - typical cheap shed has no diagonal bracing, so does not have much resistance to racking forces - a sheet of OSB nailed to one end and one side wall will stiffen it up

 

[powertools]

I have 2 wooden sheds. One was given to me second hand about 40 years ago and the other i purchased new at about the same time.
Both are still going and have survived 3 house moves but have always been erected correctly with plenty of air flow all round and in my opinion most importantly both have guttering to keep water off the sides.

 

[graduate_owner]

I treat our wooden sheds every 3 or so years, especially the lower 18" or so. Both interior and exterior get done. I use a spirit based preservative for the exterior sections because I think it gives better protection. I think Cuprinol etc are probably the best but also the most expensive, so I buy Barretine which is about half the price.
I don't think much of that waxy stuff like Duck's Back. It keeps the water off but doesn't penetrate the wood.

The roofing felt that comes with sheds is usually rubbish. I recovered one shed with proper green mineral felt on top of the old felt and sealed joints with an acrylic sealer ( aquacryl?). On the other shed I bought box profile steel sheets which cost about £250 for a 24 x 16 ish shed. Should outlast felt many times over.

So, for what it's worth, that is my strategy for prolonging shed life. I-m sure the other suggestions such as guttering, keeping off the floor etc are well worth taking on board where possible.

K

 

[DTR]

Thanks for the reassurance Chaps, I feel a little better now

Keys to long life of any wooden structure IMHO:
1. Keep the bottom of the walls dry by getting it off the ground and incorporating damp-proof course under any wooden bearers - and accept that wooden bearers might have to be replaced every 10 years anyway

This is probably my main area of concern. Walls and roof can be repaired, but how does one replace a rotten bearer when there's a shed on top of it?! The bearers sit on top of a concrete plinth about 4" above the surrounding ground level, but there's no damp course. The plinth is the same footprint as the shed so it doesn't catch much rain.

2. Replace the felt roof before it fails -- that way the water will not have got into the wooden structure and started to rot it - box profile steel is not that expensive on a big shed and not much harder to fit than a felt roof

The roof was re-felted with decent stuff a year or two ago. The naff kit felt was getting a bit knackered after a few years.

3. Consider upgrading some of the internal studs if they are less than 45x45 - they dont have much meat in them

I forgot to mention that the bearers are more than 45mm square, so no problem there. I have been contemplating installing insulation (e.g. Celotex) then boarding over the top. I just a bit wary that I was chucking good money after bad.

 

[t8hants]

Another forum I go to has just a string about WW1 army huts still in use, and there are a surprising number, so 100 years plus is possible.

 

[No skills]

At the risk of sounding like trigger from only fools..

My dad had the same shed for 30 plus years - was made from a quality red wood from what I could tell. It sat on a concrete plinth. I think it was re-felted 3 times. The floor went rotten when I was in my early 20's - I cut it out from the inside and replaced it with treated battens and ply, the windows were knackered and got replaced with bits of osb.
We took it down last year (I'm 41 this year ) as it had enough and was falling apart, and put up a diy store thing that won't last 5 years.

I think the key to its survival was coats of proper creosote it used to receive for the first half of its life.

 

[DTR]

100 years plus is possible.

That should see me out, I think

 

[powerhand]

I inherited a shed from previous house owners. Part of it is sheltered by trees etc but this means that part of it is always in shade. As a result the areas that don't get much light/air have rotted away. I think regular painting would have prolonged its life, but I think having too much foliage around it may be detrimental long term.

 

[heimlaga]

A well built wooden shed often lasts 200-300 years though it may under fortunate cirkumstances last 800 years or more.
The oldest one I have repaired was built in 1693.

A standard mass produced British wooden garden shed on a just 4" high plinth is not likely to last all your lifetime unless you are into basejumping in your sparetime and tear down asbestos withour protection at work 5 days a week and play russian roulette with your mates every friday evening.
Hence I don't think you should put too much time and money on improving it. 16mm siding is way too thin to last and I doubt there is enough of a frame to stand on it's own when you shift the siding. The plinth should be at least 30 cm high or the sills will rot over time.

 

[Beau]

Keys to long life of any wooden structure IMHO:
1. Keep the bottom of the walls dry by getting it off the ground and incorporating damp-proof course under any wooden bearers - and accept that wooden bearers might have to be replaced every 10 years anyway
2. Replace the felt roof before it fails -- that way the water will not have got into the wooden structure and started to rot it - box profile steel is not that expensive on a big shed and not much harder to fit than a felt roof
3. Consider upgrading some of the internal studs if they are less than 45x45 - they dont have much meat in them
4. Consider installing some diagonal bracing - typical cheap shed has no diagonal bracing, so does not have much resistance to racking forces - a sheet of OSB nailed to one end and one side wall will stiffen it up

This plus a cote of creosote.

I picked up a SH shed that was starting to rot. Only to be used for poultry so slapped some creosote on the sides and some corrugated on the roof. Its not visibly deteriorated since and that was around 7 years ago.

 

[bertikus_maximus]

I think it depends upon the foundation it is upon and the care and attention you put into upkeep.

I have a shed in my garden which, although I can't date exactly, shows evidence of having been erected in the 1950s. Admittedly, it needed some serious stabilising and one side rebuilding when I came into possession of it (I bought the house, an old 1925 semi-detached affair that's only ever had 4 owners) but I would suggest that is because the people we bought the house off were/are muppets and clearly didn't look after it: for example, the roofing felt had been allowed to fall into disrepair and windows had been smashed and not repaired.

The chap who put it up (and I am lead to believe lived in my house from leaving the armed forces post-WWII until he died around late 1990s) clearly knew what he was doing as the foundation is solid and, largely, the timber is in a good state of repair.

So, as long as you look after it, there's no reason you can't make your shed last.

 

[monkeybiter]

I am a big believer in a big roof overhang where possible for garden buildings, it can keep a lot of the rain off the walls, and while admittedly my continually growing and evolving workshop is block built it is bone dry in all seasons. This is possibly helped by the fact that it's not particularly airtight and I rarely heat it.
Just remembered I have built a small wooden wood shed on the end which is not really comparable because it's mostly under an extended barn type roof but when I built that I made metal 'feet' or standoffs that I screwed the timber frame to, keeping it secure but lifting it an inch or two off the concrete base. Maybe you could carefully jack your shed up onto non rotting supports?

 

[RobinBHM]

a timber shed can last forever, even a cheap one

..............just like triggers broom

 

[DTR]

The overhanging roof is an interesting idea, it certainly sounds feasible. I'm not sure about jacking it up though; it's 16' x 10' and naturally it's fully laden....