Workshop the second

[themack]

Last year I build a workshop from a kit...see here...
Thread 'New workshop question' https://www.ukworkshop.co.uk/threads/new-workshop-question.145921/

Well, fast forward one year and I am brave and humble enough to say, it was a disaster. I am sharing this to prevent others of making the same mistake. Lack of insulation and despite adequate ventilation lets my machinery rust even so I covered them with cloth and oiled the cast iron surfaces and blades. All the other things were stored in plastic containers (like Festool boxes) and they suffered condensation too. Needless to say all smaller stuff has now been moved into warmer areas and the big stuff just needs continues oiling until I found a solution.

Now I am looking at a new workshop building. I have space for a 10x13. I will not selfbuild and therefore looking into shedbuilding businesses. There are companies which offer garden rooms made from wood or composites and different types of finishes . They deliver and install, but the customer has to provide the base and an electrician has to be hired to connect and put sockets/lights and consumer unit in. Other businesses offer the whole package from start to finish.
I am wondering what I shall go for: Wooden or composite or metal? What base? Old fashioned reinforced concrete with dampproofing or those ground screws ? How much insulation? 25mm or 40mm? I was thinking of not having the standard glass patio door like doors and opt for 3 small windows and full UPvC doors with proper locks to prevent break ins. Looking at the internet and the options, my head is spinning. Perhaps someone can help me out to make a rationale decision?

Thank you Sandra

 

[Spectric]

Wood is a good option, probably why they build log cabins in cold places like Alaska. Not all UPVC doors are the same, even the best can be let down by a poor euro lock so maybe put the money into a good solid wooden door with heavy duty clasp and locks, plenty of info to be found on the UKW if you do a search as security comes up regular. Then to prevent damp you need ventilation, warm air holds moisture. A solid concrete base is an easy option and a few courses of brickwork to sit the building on. If you are not getting involved in the build then getting a single company to do everything regards the building might be easier and then just get a decent electrician in to give you power.

 

[Jameshow]

Given your location would be looking at a dehumidifier which I would expect will give you a litre of saltwater a day!

Wood will help reduce the moisture as it will soak it up. I don't think ventilation in a very damp environment will actually help better to keep the interior much less damp that the outside atmosphere??

 

[Katomi woodsmith]

A plus one for wood.
Depending on the roof insulate the roof , decent fan and dust extraction
Electrical… work out how many lights you will need. Draw out how where
Plug sockets.. um in my humble option work how many you think you need then double it
Better to have a few unused than trying to find one to use and or overloading a scocket.
Less extension leads and multi way plug adapters the better
Just an option so use/disregard no offence taken

 

[flying haggis]

I would nr trawling round a few of the local shed builders and looking at their products and getting quotes. better to see their work in the flesh rather than a website. most places can build to your size.
just from googling i found
https://www.bramwoodtimber.co.uk/

https://www.shedsahead.uk/

I dont know them personally but when I built mine some of the places wanted silly money and others could do it for less than i could buy the timber for..

 

[Shavingsnotdust]

I finally got my new workshop four years ago (after a 15-year wait) and, like you, struggled with too many options. The build I ended up with has worked extremely well (apart from a leaking Velux window in the roof which was easily solved) - it is dry enough to store tools and machinery without rust, very easy and relatively cheap to heat and a pleasure to work in. The build consists of:
- concrete base (on DPM) 6" thick on top of which is a four-inch layer of insulation with chipboard laid directly on top. I was a bit concerned whether this would deform under the weight of machinery but it hasn't been an issue, and the absence of wooden joists solves the problem of the cold coming up through them.
- dwarf wall of single layer of concrete block with damp-proof course on top
- the walls were made as panels in the workshop and erected on site. They are simply OSB with 2x4 studs at 40cm (?) centres. The gaps between the studs are tightly filled with insulation board - 4 inches thick. On the outside of the OSB is a moisture control sheet, then studding , then oak board in a hit-and-miss pattern apart from the back wall which is not visible so was clad in wiggly tin. On the inside is a vapor-control layer then plywood cladding.
- the roof is pitched with rafters which carry the purlins to support the tin cladding. The roof has 4 inches of insulation between the rafters then a 'space-age' blanket - insulation wrapped in tin foil - on the inside which helps prevent cold ingress through the rafters. The builders went a bit mad and put plasterboard in and skimmed it - ply would have been fine!
- Windows are double-glazed as are the two skylights, door is oak ledged/framed/braced design with a good lock.

I did all the groundworks, cladding and finishing and doors etc. but the builders made and erected the frame and put the roof on.

I think I learned two things I would pass on:
1 - you cannot have too much insulation.
2. Using the correct type of moisture barriers in the correct place is essential to controlling damp. Being a wooden shed the cladding absorbs a lot of water and you need to make sure this will not permeate through.
The moisture control measures and insulation work together to avoid the biggest problem I used to get, which was warm/damp air after a cold spell. Warm/wet air contacting cold metal surfaces will inevitably lead to rust, no matter what protection you put on the tools.

Hope this is helpful

 

[alex robinson]

I would agree - you cannot have too much insulation! My workshop is a pre bought shed that came with the house. The first year I had it, everything went rusty. Installed PIR (40mm) in the walls and space blankets on the roof and all the rust stopped. Don't know what you are thinking of for the roof, but edpm is miles better than felt (but not nearly as good as insulated metal panels).

I recently built a huge shed for my parents. This was a rebuild of an old outbuilding, so I couldn't lay a new floor. Despite this it has a damp proof membrane and 40mm of PIR under the floo along with DPC under the brick low walls. 100mm in the walls and 80mm SIP roof and it is warmer than my house.

I know you want to buy not build, but make sure the base is good! That is the one bit that cannot be changed and will make your life so much easier.

 

[themack]

Good morning all
thanks for all your thoughts and input so far. And thanks for the links as well. Yes, we have quite a few shed companies around and I visited two so far, but found it a bit mindboggling. I built the last one and I found it difficult on my own hence I will have it built. I don't mind doing the inside and insulation, but not the actual frame. The roof.. I will definately have EPDM as I cannot be bothered to keep relaying felt. I won't be saving on that. We live in a dampish sea side place and my current shed has soaked up all the dampness from the outside and passed it on to the inside, because it's single skinned. Simply, it was a mistake. Looks like the majority favours wood and it is a question of proper moisture barriers in order to keep the moisture out. I will visit a couple more today to have a look .

 

[alex robinson]

Good morning all
thanks for all your thoughts and input so far. And thanks for the links as well. Yes, we have quite a few shed companies around and I visited two so far, but found it a bit mindboggling. I built the last one and I found it difficult on my own hence I will have it built. I don't mind doing the inside and insulation, but not the actual frame. The roof.. I will definately have EPDM as I cannot be bothered to keep relaying felt. I won't be saving on that. We live in a dampish sea side place and my current shed has soaked up all the dampness from the outside and passed it on to the inside, because it's single skinned. Simply, it was a mistake. Looks like the majority favours wood and it is a question of proper moisture barriers in order to keep the moisture out. I will visit a couple more today to have a look .

I wonder how much the dryness of well lined sheds is as a result of moisture barriers and how much as a result of decreased fluctuations in temperature. My workshop doesn't have a moisture barrier. An uninsulated shed will get warm in the day (especially with a black roof), warm air holds a lot of water. It will then get very cold during the night - the black roof now radiating correspondingly more heat. This will condense the water. The very few times things have been damp in there have been after rapid temperature changes when the weather suddenly warms after a long period of very cold conditions.

Are you going to demolish the old to make space for the new? If not, you may be pleasingly surprised by what jamming PIR between the uprights, insulating the roof and boarding with thin ply will achieve.

 

[themack]

No, I am not going to demolish the old one, I just store non rustable things in it. I have enough room for a 10x 13 shed adjacent to it.
The old one is a very cheap one with feather board cladding . I sealed it all off with CT1 and the wood still moved, cracked that and it is just a nightmare. Not worth insulating that one. It was just a big mistake of mine to think I could make a parlour for woodworking out of it .
The new one will go where I have the polytunnel sitting (one can see the edge in the second picture)

 

[alex robinson]

No, I am not going to demolish the old one, I just store non rustable things in it. I have enough room for a 10x 13 shed adjacent to it.
The old one is a very cheap one with feather board cladding . I sealed it all off with CT1 and the wood still moved, cracked that and it is just a nightmare. Not worth insulating that one. It was just a big mistake of mine to think I could make a parlour for woodworking out of it .
The new one will go where I have the polytunnel sitting (one can see the edge in the second picture)

Each to their own, but I think you would be pleasantly surprised how much of a difference it could make. Even if it is never going to be an A grade workshop space, it could take you up to something less soggy!

 

[Ross Buchanan]

With workshops, one needs to completely change the way you approach it.
Instead of thinking of a wooden shed, plus some insulation you need to imagine an insulated box, with a weatherproof cladding envelope.
If you put 100mm of insulation down below the floor, with 22mm caberfloor. Then look to 150mm of wall insulation- 100mm between studs with 50mm overlay, joins all taped. 150mm of roof insulation. Decent quality double glazed velux/windows and insulated doors.
You can then keep that space at a sensible temperature with a 200 or 300w heater, and it will retain that temperature.
I know PIR insulation is a significant investment these days, but in the long run it is better than rusting tools, warping wood and an inhospitable atmosphere.

 

[MarkAW]

Good morning all
thanks for all your thoughts and input so far. And thanks for the links as well. Yes, we have quite a few shed companies around and I visited two so far, but found it a bit mindboggling. I built the last one and I found it difficult on my own hence I will have it built. I don't mind doing the inside and insulation, but not the actual frame. The roof.. I will definately have EPDM as I cannot be bothered to keep relaying felt. I won't be saving on that. We live in a dampish sea side place and my current shed has soaked up all the dampness from the outside and passed it on to the inside, because it's single skinned. Simply, it was a mistake. Looks like the majority favours wood and it is a question of proper moisture barriers in order to keep the moisture out. I will visit a couple more today to have a look .

I noticed you said seaside. That environment is notorious for having salt in the air. Salt speeds up rusting. it can be quite substantial near the sea front. I recommend insulating and sealing rather than ventilating. Also spec any fastenings (screws, locks etc) on the outside high.
That would also sway the decision away from metal for me.