Increasing height of sectional garage

[Scott Duffy]

Hi Guys,

I converted my external sectional garage into a photography studio and for the first months everything was fine but since last winter it's been a nightmare. I floored it with rubber mats and used chipboard loft flooring for half of it with white vinyl which worked well. The issues i had was with damp and ceiling height. I had used the foil insulation sheeting and plasterboard on the walls and added a pvc front door. The ceiling is asbestos sheets and i was advised to leave these as they were and just paint them so as not to disturb them. I knew nothing about condensation and put elslectric heaters in it and lighting. I am at the stage now where i have to completely strip it and start again as the mould is ridiculous.

Now my questions are

1, How do i raise the height of the walls to allow an indoor working height of 8 feet?
2, What insulation should i use in the walls and ceilings?
3, Should i put something down on the concrete slab before the rubber tiles?
4, Would i be better getting rid of the sectional garage all together and either building a block studio or wooden one?

I don't have a huge budget so money for this is certainly a factor especially as i blew quite a bit first time round and have nothing to show for it.

Thanks in advance.

 

[Harry Bloomfield]

Simple answer, get rid and start again. Other options, ignoring any permissions needed...

1. You could maybe convert the roof to an apex type roof, rather than the flat one you have, using timber home-made A frames to give a bit more height.

2. You might be able to build a dwarf wall, then lift and rebuild the panels onto the wall - though I have never heard of this being done.

3. A combination of 1 and 2.

Be aware that the concrete sections are very heavy, around 2cwt each and there is nothing much keeping them upright, apart from the one next to it and the roof timbers.

 

[Scott Duffy]

I had actually decided to take it down and build another but thought I'd ask here first. If it is a timber one i build i can do all the work myself as my father in law is a retired joiner so he'll help me and keep me right.

The apex roof idea i thought of but was scared it would put pressure on existing walls. The dwarf wall seems like an idea but i wouldn't have the first clue whether it would be stable enough sitting the garage panels on it and it would be quite a lift up onto a 2 foot ish wall.

I think i might be choosing between wood and block. Will wood last if it's cladded properly?

 

[Luckyphil]

Hi , some of the new Garages from Lidget / Compton have a stud Wall built on top of the existing panels to raise the Height , if you’ve got an Apex Roof or Pent Roof you could gain an extra Foot in height and clad the outside ,

I often convert these Garages into Offices / Gyms / Playrooms , we usually stud out the Walls & Ceiling with 3x2 Timber then infill with 2” Kingspan then overlay with 1/4” good faced Plywood , I’ve found in the past Plasterboard tends to degrade & fall apart over the years , as for the Floor I doubt there’ll be a membrane in it. So it might be an idea to lay Visqueen them floor it , also consider replacing the Roof , with a Corrugated Tin Roof with a liner on the inside to stop condensation

regards

Phil

 

[Scott Duffy]

Thanks Phil. Would the stud wall need bracketed onto the existing sectional walls or would i have timber posts from the floor level up? The roof just now is slightly sloped but asbestos sheets so I'll look at the sheets you've mentioned above. The visqueen is a good shout as some of the damp seems low so probably coming in from the floor. Thanks again.

Hi , some of the new Garages from Lidget / Compton have a stud Wall built on top of the existing panels to raise the Height , if you’ve got an Apex Roof or Pent Roof you could gain an extra Foot in height and clad the outside ,

I often convert these Garages into Offices / Gyms / Playrooms , we usually stud out the Walls & Ceiling with 3x2 Timber then infill with 2” Kingspan then overlay with 1/4” good faced Plywood , I’ve found in the past Plasterboard tends to degrade & fall apart over the years , as for the Floor I doubt there’ll be a membrane in it. So it might be an idea to lay Visqueen them floor it , also consider replacing the Roof , with a Corrugated Tin Roof with a liner on the inside to stop condensation

regards

Phil

 

[Scott Duffy]

Phil do you know if thermawrap insulation would stop condensation on the underside of the roof sheets if i stuck it on under there with some sort of adhesive?

 

[Harry Bloomfield]

Phil do you know if thermawrap insulation would stop condensation on the underside of the roof sheets if i stuck it on under there with some sort of adhesive?

Any insulation will help. My own roof sheets are metal now and I had a condensation issue. I fixed it by insulating.

 

[cdbe]

I would agree that if budget allows then definitely start again - but people seem to pay many thousands for a new garage (especially when built to habitable standards).

If you're skint and handy (and have a joiner on hand) these old garages can be refurbished at a fraction of the cost (but still high hundreds/low thousands for a nice job). Roof needs to go, some local authorities will still take them from householders for free and it's safe to do with a few basic precautions, you can build up the walls with timber to raise the height of the new roof (tile effect steel roofing sheets are a good budget option). I would recommend a cement based cladding (Marley cedral or similar) for fire/weather resistance/maintenance. You can insulate between shell and cladding to avoid loosing internal space. Check the floor height, garages are often at external ground level and need to be raised up - gives the opportunity to add a new insulated slab and dpm.

Beware of sticking expensive tin foil on the roof, it's throwing more good money after bad, in the short term some high level ventilation would be better - you need to get the warm moisture laden air out of the building. You can get sheets with an anti-condensation layer but all it does is soak it up so it (hopefully) evaporates and drifts outside later rather than dripping on you - some old bed sheets draped up would do the same thing.

Mine is just a workshop and awaiting some new cladding and a nicer looking roof covering when I get round to it, but its insulated and dry. Windows and doors from eBay and the inside is fully lined in some 18mm shuttering ply that I picked up.

 

[Scott Duffy]

Thanks buddy. I will certainly take these points on. If i was say placing a new floor on battens would i just lay the visqueen over the concrete slab and then tape it to the walls? I am not 100% yet on how the wooden frame at the top would be attached to the wall panels. Would it need supported from the ground with posts as i would be concerned that the wooden section would collapse or even worse collapse the whole structure.

 

[Scott Duffy]

I've just been speaking to my father in law (joiner) and he's said that he's sure he remembers being told never to drill through pre cast concrete garage panels like we would have to to attach a frame because apparently they're liable to crack badly which would affect the strength of the building as a whole. Anyone know if this is correct? We had been discussing screwing some timber battens across the outside and cladding it. The battens would obviously have given the building the 8ft height i was seeking.

 

[Notch7]

Will wood last if it's cladded properly?

yes indeed

I built a timber framed garden office -it is as dry and warm as the house (mind you it has 120mm celetex in the roof, 100mmin the walls and 70mm in the floor)


you either need to start again, or use the concrete garage as a shell and build a new weather tight skin a cavity or damp membrane

Ideally you want to line the inside because if you clad externally the cold concrete will still be internal and its sitting on a cold slab

you could strip out the internals and roof, build a 3 x 2 or 4 x 2 frame internally and say 8'0 tall....
then form a now roof on top of the 3 x 2 walls which extend beyond the concrete walls.

you would lose some internal space of course.


your current issues are caused by a lack of damp arrangement and thermal bridging

 

[Scott Duffy]

So if i build a frame on the inside what's to stop the heavy sections of walling from collapsing? I am assuming that a big part of the stability is the roof frame sitting over them but if a new roof is higher then what's giving them the strength to stop collapsing? Hope that makes sense.

 

[Notch7]

So if i build a frame on the inside what's to stop the heavy sections of walling from collapsing? I am assuming that a big part of the stability is the roof frame sitting over them but if a new roof is higher then what's giving them the strength to stop collapsing? Hope that makes sense.

I presume at the moment there are some steel angles going from one side to the other at the height of the walls?

your new studwork structure could be built at say 8'0 -at that point you need common joists going from side to side

externally at just above the top of the concrete walls, you will need a timber plate screwed to the new studwork so its sitting just on top of the concrete walls and then some fixing points to those walls

if you want to clad externally, then fit vertical battens over the concrete walls and the bit of studwork at the top


you would effectively be making a new structure around the existing -but it would be cheaper and less work than starting from sratch

 

[Harry Bloomfield]

I've just been speaking to my father in law (joiner) and he's said that he's sure he remembers being told never to drill through pre cast concrete garage panels like we would have to to attach a frame because apparently they're liable to crack badly which would affect the strength of the building as a whole. Anyone know if this is correct?

The cast panels are very thin, very hard and reinforced with steel, so don't drill them. I would suggest finding some other method - making a steel bracket to use the panel to panel bolts, extending the timber frame a little way down the panel. The panels should take the weight of the roof as before, with the brackets just keeping the supports in place and stabilising the panels side to side. You may need some temporary bracing of the panels, until your roof is complete - they only sit on a 2" wide base.

 

[Scott Duffy]

Thanks guys. You've been a great help. I'll let you know how i get on.