Garden office heating

[Fender Stratoplaster]

Hi all,

We've just ordered a cabin from Creative Living garden cabins for me and my partner to work from as our office, the cabin itself is insulated on the base and the roof, it has double glazed windows and door and wood cladding on the walls but the walls themselves aren't insulated...

They say as the wood flexes they don't provide insulation and there are no cavities within the walls to add.

Firstly...

- What are peoples recommendations for heating this space?

We are considering a wall mounted oil heater, or would it be possible/better to get a wall mounted electric radiator? We will have mains power run to the cabin, a box has already been installed on the outside of the house with shielded cable to run. Can you mount either of these radiators on the wood cladded walls and is it safe?

Secondly...

- The company claims good heat retention within the heated space (they would) does anyone have any experience of the reality of this? We are aiming to be working in there nearly 5 days a week so i'm dreading the potential costs during winter time


Thirdly...

Is it possible to retrofit any insulation given what the company has said about wood flexing?


Thanks in advance all for your help!

 

[JohnD]

wooden buildings usually have a timber frame with cladding nailed to it.

people wishing to insulate them usually put insulation between the timbers of the frame.

sheds usually have no internal lining, but posher buildings usually have ply sheets or other material nailed to the inside of the frame, so insulation can go between the inner lining and the outer cladding. Plasterboard is a fireproof material but will not withstand damp and can be damaged if struck by hard objects.

there may be a water-resistant membrane or felt inside the outer cladding to resist penetration of rain and draughts

photos of your building or sketches of its construction would be very useful.

 

[Fender Stratoplaster]

wooden buildings usually have a timber frame with cladding nailed to it.

people wishing to insulate them usually put insulation between the timbers of the frame.

sheds usually have no internal lining, but posher buildings usually have ply sheets or other material nailed to the inside of the frame, so insulation can go between the inner lining and the outer cladding. Plasterboard is a fireproof material but will not withstand damp and can be damaged if struck by hard objects.

there may be a water-resistant membrane or felt inside the outer cladding to resist penetration of rain and draughts

photos of your building or sketches of its construction would be very useful.

Thanks for the reply, I don't have any photos of ours as we haven't had it installed yet but you can see examples of it here:

Berkshire Log Cabins by Creative Living Cabins | Garden Offices & Much More!

Welcome to the Berkshire Log Cabin | Our Berkshire log cabins are one of our best selling cabins, & we have just recently made even more improvements to the design | Free Quotes

www.creativelivingcabins.co.uk

I don't really see anything obvious that points toward the inside of the timbers, especially in the cross section photo on that page

 

[JohnD]

oh, it looks like it's made of T&G logs with notches at the end for interlocking.

unless it is built to american style, the "logs" will be 8x2" sawn timber, or similar, with a flattish face.

you could attach insulation and a lining on the inside.

PU slabs such as kingspan or celeotex would be suitable.

the boards will expand and contract a little depending on the weather, so probably hang them from the top rail rather than fixing them at multiple points.

if you use a slab with a bonded plasterboard face, this will give you a surface you can paint or decorate.

if you want a non-flammable lining, you could use mineral wool and plasterboard, but I think it will need battens to provide rigidity

 

[Fender Stratoplaster]

oh, it looks like it's made of T&G logs with notches at the end for interlocking.

unless it is built to american style, the "logs" will be 8x2" sawn timber, or similar, with a flattish face.

you could attach insulation and a lining on the inside.

PU slabs such as kingspan or celeotex would be suitable.

the boards will expand and contract a little depending on the weather, so probably hang them from the top rail rather than fixing them at multiple points.

if you use a slab with a bonded plasterboard face, this will give you a surface you can paint or decorate.

if you want a non-flammable lining, you could use mineral wool and plasterboard, but I think it will need battens to provide rigidity

Thanks for the info, I'm assuming if we intend to hang a radiator on the wall after plasterboard etc. it should be okay given electric radiators are lighter weight - the non-flammable lining sounds like an essential given electrics etc.

When you say hang the boards from the top rail, do you mean they are kind of floating?

I'll have a battle on my hands if we do go down this route as we'd lose the wood aesthetic for smooth walls, but I'd take the increased thermal performance any day

 

[Mike13]

Hi,
This page will guide you to the heat-loss for your cabin, as with a log cabin you can get thicker or thinner walls.

Double Glazing in Log CabinsTuin Blog

The Tuin site seems to have a lot of good info, and does explain why they dont recommend the double skin log cabins.
basically the inner wall and outside wall are at such different temps and humidities that the wall does not hold together properly.

 

[Fender Stratoplaster]

Hi,
This page will guide you to the heat-loss for your cabin, as with a log cabin you can get thicker or thinner walls.

Double Glazing in Log CabinsTuin Blog

The Tuin site seems to have a lot of good info, and does explain why they dont recommend the double skin log cabins.
basically the inner wall and outside wall are at such different temps and humidities that the wall does not hold together properly.

Thanks, this was interesting reading - I've checked the cabin we ordered and the wall logs are 42mm so bit under the recommended thickness for garden office thermal performance.

Do you think this along with floor and roof insulation and double glazing will just about scrape it?

 

[big-all]

in my humble opinion expect it to be perhaps up to 2kw to heat on cold days every hour all depends on heat loss so expect 40p an hour ln cold days so on an average 7 hour day you may be talking £3 day or £20 a week or 90 a month without added insulation but all depends on actual loss and expected heat

 

[Mike13]

We put 70mm below and above along with double glazing, but are not using ours as an office. So I reckon Big-all's estimates would be about right. Dont forget that a log cabin expects to grow and shrink in height with the seasons, so hanging insulation needs to be done carefully with slotted timber uprights, like they do with the external strap to stop it lifting the top off in high winds.

 

[Fender Stratoplaster]

Another question I had - we've got a cable run by electricians from fuse box to edge of patio so we can put a shielded cable in a trench to the cabin

Although there's 2 outlets in the box on the patio, there's only one cable that's been run to it and we were told by electricians the outlets are 4mm - which might not be enough to run the whole cabin without things tripping. They recommend 10mm cable but I'm hearing max is 6mm anyway

Is this true? Or an attempt to make a bit more money out of us?

We'd have 3 x double power sockets inside, one of those would have a 2kw wall mounted electric radiator plugged in, the other two would have power for the misses laptop and possibly a fan during warm weather and the other one would have my laptop plugged in and phone charger etc. Also just normal amount of lights, couple of external lights too

Would also look to move my guitar amp in there too and run from time to time

Should this be adequate for all the above?

Also, to run a WiFi cable f4om the house to the cabin is super expensive - is it possible to get by on a booster for video calls?

 

[Mr Chibs]

I had an armoured cable run... a larger rating than anticipated... when I questioned the sparky, he said it was due to the size of the earth conductor/wire, it needed to be a certain rating and that came with larger diameter cable.

 

[oldbutnotdead]

WiFi cable? Really?
Have you already filled in the trench with the power cable in it?
All you need is some 50mm ducting and a drum of CAT5E. Dig a trench -a foot deep will do but go deeper if you can. Chuck duct in. Pull cat5E through (2 runs is sensible, more if you want to extend house alarm system to shed). House end goes to wherever your broadband router is. Put a socket on the end of it (much easier than trying to crimp a plug on the end), use patchcord to connect to router.
Shed end connect to router/switch/hub of your choice.

 

[Fender Stratoplaster]

WiFi cable? Really?
Have you already filled in the trench with the power cable in it?
All you need is some 50mm ducting and a drum of CAT5E. Dig a trench -a foot deep will do but go deeper if you can. Chuck duct in. Pull cat5E through (2 runs is sensible, more if you want to extend house alarm system to shed). House end goes to wherever your broadband router is. Put a socket on the end of it (much easier than trying to crimp a plug on the end), use patchcord to connect to router.
Shed end connect to router/switch/hub of your choice.

Thanks for the advice - why use CAT5E over CAT6? And when you say do 2 runs - is that 2 x cables run to the shed in case one fails?

We've been quoted by the cabin suppliers recommended electrical company £420+VAT - seems like a lot of money to me!


Any advice on running the 4mm power cable to the shed? They are going to do this for us but no guarantee it won't trip under load - the alternative for them is to install 10mm armoured cable from consumer unit inside the house but to do this they'd want to hack away the new render we have had done and feed around the outside of the house

 

[oldbutnotdead]

CAT6 is a pain to terminate, far more critical on bend radius, unless you actually require that performance level CAT5E is much easier to handle and terminate. Bonus of ducting- you can add or replace in the future if you need to. 2 runs- yes redundancy or load sharing (you could dedicate one run for media streaming, use the other for everything else).
What's the distance from shed to CU? 4mm might be a bit puny over 30 metres assuming your heat load (2kw) will be pretty constant and you'll be boiling a kettle every so often.
Is that £420 plus quote for supply and fit (including digging to required depth) swa and data (not a bad price length dependent) or data only?

 

[Fender Stratoplaster]

CAT6 is a pain to terminate, far more critical on bend radius, unless you actually require that performance level CAT5E is much easier to handle and terminate. Bonus of ducting- you can add or replace in the future if you need to. 2 runs- yes redundancy or load sharing (you could dedicate one run for media streaming, use the other for everything else).
What's the distance from shed to CU? 4mm might be a bit puny over 30 metres assuming your heat load (2kw) will be pretty constant and you'll be boiling a kettle every so often.
Is that £420 plus quote for supply and fit (including digging to required depth) swa and data (not a bad price length dependent) or data only?

Ah thanks, makes sense on CAT6 - I'd read about the bend radius being an issue. If we did CAT5E we'd plan to connect it to a wireless router inside the cabin so we could connect with our laptops. Are you suggesting to hardwire all devices?

The distance would be 17metres total from consumer unit - cable has already been fed under patio and to an outside box in a straight line, imagine there's possible 8 metres from box to the cabin?

£420 is without the trench being dug, they refuse to do it and will only lay if we dig a 60cm trench ourselves. Their preference is just to lay the cable along the bottom of the patio edge on the grass, around the outside of the garden along the fence line where we have soil and plants etc.

We were looking into all options - wireless booster, point to point, powerline networking... how would these hold up for 2 x people simultaneously video calling?

Thanks for your advice - really helpful