Replacing a ?tin? roof, any pointers?

alastairgott

alastairgott

Well-known member
Does anyone know anything about metal shed/garage roofs. Just been asked about what quality we want and to be fair I haven?t a clue.


I think the red rose (bull pot) hut has a metal roof, so just interested if there?s anything I can glean in terms of budget (and cold) vs expensive (and quality warmth).


And if anyone knows where the good middle ground is.
 
The main issue with a tin roof is condensation I think. This will be a particular issue if you are drying wet caving gear in there.

A plywood deck below the tin might solve this inexpensively. But you would probably want to consider the ventilation between layers. If I recall, I believe the technique is to run battons up the ply, then counter-batton across, then fix the tin cladding to these.

For a shed, I can't see any point in a warm roof, but I guess that depends what you are using it for. If it's your workshop where you will spend 8 hours a day, it's probably worth it.

Personally, I'd be using something cheap like galvanised corrugated iron, but it doesn't look great. Depending where you are, you might also need planning permission, which would require specifying the materials. In a conservation area you might be forced to use something expensive...

Edit: should probably point out that I'm not an architect and I know sod all about ventilation and insulation, but I've seen a  fair few details as a structural engineer...
 
If it?s a small shed and you no any local farmers they normally have lots of off cuts due to all the grain stores now days are built in this for roofs also their stuff is the highest quality
 
It's a double garage sized space and we're trying to figure out how thick the bonded insulation foam needs to be on the roof panels (and then if we can afford it!).
 
So under the sheets you want 80mm - 100mm to insulate it depends on what the garage is going to be used for really ?
 
Storage, changing, hanging kit up to drip dry without freezing solid in winter. It won't be an 'occupied' space, more like a utility area and workshop. It won't need insulating to the same standard as a normal internal house or workplace space, but some insulation would improve it and the roof needs doing anyway. We're just not sure how much insulation is needed really.
 
I would go around the 50mm mark then that way your safe either way , you could still go a bit less to be honest 40mm would still work and do it?s purpose  and it?s cheaper you should search the internet for offers of buying +5 sheets unless you have a builders merchants account or no somebody with one they normally get 30% of
 
Other option is a linear sheet with a z bar in between them so in theory you have to roofs this stops condensation  and doesn?t need insulation, I would make sure your  ends and sealed up well with fix all for example and your screws are decent , it?s common the seals around the screws leak when cheap and after all the money / effort you don?t want a leak  :thumbsup:
 
During the last lockdown I built myself another shed. It is a concrete sectional one with a single pitch roof. I put plywood sheets down first then 30mm of Kingspan sheets, then box profile cladding sheets. It has upvc windows and door. Unfortunately, I think I made too good a job of sealing it all up and I am now getting mould on the plywood inside. I think the lesson here is that you must have some airflow inside to get rid of moisture. When the weather improves, I will have to cut some vent holes to try and get round this problem...

Les
 
Definitely need the ventilation especially for the purpose of having wet clothes in their to dry , a good idea is to bang a fire place inside of it or a log burner even and leave the door wide open that way you have the Benefit of it in the winter  windows are good if you can leave open but depends if you have the issue of theft . Much to think about
 
Why on earth bother with insulatiin if the space is not heated and any heat will be lost via draghts anyhow.
 
For the age-old reason that it's hot in summer and freezing in winter, and if we have ten hot bodies in there getting changed after a Peak trip in winter (oh, those heady days), the place will warm up quite quickly, instead of those poor kids going blue and shaking uncontrollably. The walls are a foot thick, and the draughts aren't so huge. The heating's usually on in the main room too. Simply, we're building a sweat-lodge ;)
 
Sounds like you need ventilation (to get rid of all the hot, sweaty, malodorous air) rather than insulation (to keep all that stinky air nice and warm and humid).
 
have you considered bonded insulated steel sheet via reclaimed  suppliers? have used same myself up to 5M. lengths. will post last supplier i used when i find records. they delivered too. farm recaims leek way if i remember correctly.  :thumbsup:  Ric'.
 
Speleofish said:
Sounds like you need ventilation (to get rid of all the hot, sweaty, malodorous air) rather than insulation (to keep all that stinky air nice and warm and humid).
Click to expand...

You need both; insulation and airflow.

Post up a sketch and I'll draw you up a cheap fix with some easy details.  :thumbsup:

 
I think SamT is right.
Unless you are going to do something like putting insulation on the walls (I imagine you are not) and replacing that sliding door (with a wall and a decent door) then you won?t be wanting to heat the space, and without that there is little point in insulating the roof.
I would have thought a reflective (white?) outer layer with 40 or 50mm insulation, as suggested by Down and beyond, would be about right.
That way you would at least have options in the future if you wanted to improve the performance of the rest of the structure and put in some heating.
 
50mm of bonded insulation was what I was thinking about. The garage doors are on the list for replacement with a modern sealed frontage too, so that deals with the big draft. We'll of course get vents for damp air. I'd love to insulate and clad the walls, but that is a discussion that needs to be had in future. Money prevents the lot being done in one hit, but starting with the correct materials on the roof will set us up for a warmer building further down the line.
 
You must log in or register to reply here.
Back
Top