bricking up a garage door for workshop, ideas

[BazyleParticipant @bazyle]

Posted by Oompa Lumpa on 22/04/2014 10:14:55:

If I haven't used it or had a need of it in the last twelve months then out it goes.

graham.

Does that apply to the 'fridge?

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Bazyle on 22/04/2014 13:19:25:

Posted by Oompa Lumpa on 22/04/2014 10:14:55:

If I haven't used it or had a need of it in the last twelve months then out it goes.

graham.

Does that apply to the 'fridge?

LMAO – spat my tea out as I read that. You aren't going to believe it, but I have both fridge AND freezer in my workshop/office. I was just contemplating getting rid of the fridge – because all I keep in it is bottle water (and it doubles as a shelf for the kettle) and I really must think about the 'lectric consumption. Coupled with the fact we have a massive Fridge/Freezer AND a stand alone fridge in the kitchen, well frankly I think it's a bit of overkill.

Anyone in the Manchester area want a fridge? Free to collect (please do not mention freecycle to me).

graham.

[John McNamaraParticipant @johnmcnamara74883]

Consider the following Link carefully…. LED Lights can save a bit of cash and some Coal or Uranium in the UK at the Generator, but the real enemy is heat loss….. Insulating (and) making a workshop airtight is not easy.

**LINK**

Regards
John

[Jerry WrayParticipant @jerrywray14030]

Although the issues surrounding heating, lighting, size and planning may be significant it might not be readily apparent that concrete, even after complete curing for some years is terrifically alkaline. I had a garage in Kent built of pre-cast concrete blocks which I used for storage and as a small workshop. When I came to move all the tools which I had stored but not used in the six years of occupation had heavy accumulations of rust.

I borrowed both moisture meter and the kit for measuring airborne pollutants and found that in the spring of 2003 the moisture over a 4 week period averaged ~8% but the airborne inorganic salts were off the scale. (>2.5%).Measurements made with the door closed of course, only opener intermittently during the previous winter.

20 years before that I lived on a narrow boat and stored most of the same tools on that with no problem.

It may be worth looking at the efflorescence on the concrete blocks

[John McNamaraParticipant @johnmcnamara74883]

Re efflorescence:

Some block makers offer moisture resistant concrete blocks In Melbourne Australia but I guess the same will apply in other countries? For existing walls there are special sealers and paint.

Building from scratch….
Maybe insulate the outside say rendered 100mm foam bricks on the inside?

**LINK**

Regards
John

[Bob Brown 1Participant @bobbrown1]

I think that getting a fixing into a precast concrete garage may present some problems so as far as insulation it may prove easier to construct a timber frame inside the original building. This would allow for insulation and reduce the ingress of water. The panels could be prefabricated on the floor and with a vapour barrier on the outward face, fix to the floor making sure there is a damp proof membrane between the floor and the wood to stop it rotting and then infill the spaces with Rockwool and plywood, mdf, OSB board over cheapest is likely to be OSB board. Would have said plaster board but hanging stuff on that is a pain.

I would use treated 4 x 2 through out and 100mm Rockwool with uprights at 600mm centres and the same to form a ceiling with insulation above. all the electrics can go inside the panels and it should look reasonable good.

I would budget about £1000.00 for materials and it is not too difficult for a DIY job

My garage will be brick outer skin, cavity with insulation 75mm and Celcon block inner, double glazed window and access door and a round the corner insulated garage door. Cathedral ceiling as I want to have some height for a 4 post ramp and insulated at roof level 100mm Kingspan or similar. Bit of overkill for a garage but will make for a warm workshop with out spending a fortune on heating.

[Swarf, Mostly!Participant @swarfmostly]

Posted by Bob Brown 1 on 22/04/2014 15:30:06:

SNIP

The panels could be prefabricated on the floor and with a vapour barrier on the outward face,

SNIP

I beg to differ regarding the position of the vapour barrier – I prefer it to be on the 'warm' side of the insulation. If the vapour barrier is on the 'cold' side of the insulation, any water vapour will condense there (when the 'cold' temperature is less than the dew point) and make the insulation damp. If the insulation is glass fibre and gets damp, it ceases to be insulation!

The vapour barrier isn't there to exclude rain – that's the job of the outer shed/garage walls or cladding. The object of the vapour barrier, as I understand it, is to confine any water vapour to the building interior away from the insulation. Water vapour is emitted (transpired) by the occupying Model Engineer (e.g. while testing tap wrenches to destruction! ), by visitors, by boiling kettles and by paraffin-burning heaters and LPG torches.

So, I'd say put the vapour barrier on the inside but provide for good (forced) ventilation. On the latter topic, I recommend a book entitled 'Woods' Practical Guide to Fan Engineering'. It will dispel some of the commonly-held myths about what fans do.

Also, a point about Planning Consent (see posts on the previous page): so-called 'permitted development' provisions, e.g. sheds less than 50 m³, don't apply in 'areas of outstanding natural beauty', conservation areas or National Parks. They also might not apply in 'ordinary' areas if the local Planning Authority have exercised their power to withdraw them.

Best regards,

Swarf, Mostly!

[Bob Brown 1Participant @bobbrown1]

Opps! should have said breathable membrane like Kingspan Nilvent rather than a vapour barrier.

[MM57Participant @mm57]

OK, I'm up for asking the idiot question…for the above mentioned commercial product I find an online store that says

"Nilvent is completely waterproof with an excellent water vapour permeability for a zero condensation risk. this (sic) product is fully BBA Approved."

..so it's waterproof, but lets water vapour through, so:
– how does it do that?
– why would I want something in the wall construction that does that?

[Bob Brown 1Participant @bobbrown1]

liquid v gas, so it lets water vapour through but not water in its liquid state, a case of tiny holes only allowing the individual molecules to pass not a whole bunch of them in a drop of water or something like that.

It allows the roof or wall to breath and stops damp in wall or roof structures from building up, works the same as modern clothing that keeps the rain out but breaths to keep you dry as you exercise (sweat).

[MM57Participant @mm57]

So it doesn't rain inside my shed and the material lets the water vapour through, in both directions, I presume – so what benefit does it actually bring? I must being particularly dense about this …

[frank brownParticipant @frankbrown22225]

Martin, if you just have wood, glass fibre then a brick or concrete outer surface, your moisture laden, hot breath will percolate through the wood (joints) and as it gets into the glass fibre, it cools. So at some depth of the glass fibre there is actual water, not a huge amount, but it is a pumping action. The glass fibre is not an insulator now its damp, so the water vapour condenses more readily. Eventually all these drips of water will rot the bottom of the joists, then the internal paneling. . .

***** THE FITTING OF A VAPOUR PROOF MEMBRANE IS A MUST FOR ALL TOP FLOOR CEILINGS OR AT A SECOND BEST, ALI BACKED PLASTERBOARD. ****

I have spoken to builders who have had to replace all the joists on flat roof because of this omission, and speaking to a mate of mine, he has just turned his kitchen extension ceiling from flat to vaulted without a VPM. He is as old as me so it should see out (just?) but its not a job well done. The cost is trivial, its much cheaper then DPM as its much thinner.

Frank

[MM57Participant @mm57]

…but you're talking about vapour PROOF, which I understand, but the material in question is vapour PERMEABLE (but waterproof!)

Still not clear to me…

[Bob Brown 1Participant @bobbrown1]

Martin

try this link **LINK**

Bob

[BazyleParticipant @bazyle]

Short version for sheds. On inside use everything proof eg plastic sheet. However you must then ventillate or dehumidfy to remove the moisture. If you have a roof that will sweat use an additional breathable but waterproof membrane above the insulation to stop drips sinking into the insulation. Ventillate this space under the roof. Also make sure insulation does not touch the inside of the walls and again ventillate this gap.

[GaryMParticipant @garym]

Posted by Martin Millener on 22/04/2014 17:20:13:

OK, I'm up for asking the idiot question…for the above mentioned commercial product I find an online store that says

"Nilvent is completely waterproof with an excellent water vapour permeability for a zero condensation risk. this (sic) product is fully BBA Approved."

..so it's waterproof, but lets water vapour through, so:
– how does it do that?
– why would I want something in the wall construction that does that?

Hi Martin,

Different area but Goretex jackets are waterproof but let moisture vapour out (i.e. sweat).

Gary

[MM57Participant @mm57]

OK, I get the waterproof but vapour permeable membrane. Maybe the key item is the air gaps – can't see any point in say, outside to inside, wooden wall, vapour permeable membrane, insulation, maybe poly sheet, and then internal wooden wall all sandwiched directly together?

So for my new shed/workshop, currently a shell:
– 20mm T+G (vertical) with external strips over joins for the wall, 2" thick internal bracing horizontal
– 13mm T+G roof with corrugated bitumen tiles, 2" bracing everywhere internally
– 20mm T+G floor on 2" stretchers sitting on slabs with only the corners mortared (so any really wet will fall through the cracks)
– with the slabs spotted onto a concrete base, so there's an escape route for the wet going between the slabs.

…what does the collective think I should have, outside to inside, including air gaps (and how do I get them?), for the walls and ceiling. In simple, unambiguous, words please!

I'm wanting smooth internal walls (WBP ply or ply, preferably, rather than chipboard or OSB) and willing to lose a bit of space by having thicker walls/ceiling.

(…and sorry for the massive thread hijack – will start a new thread if not acceptable)

[Bob Brown 1Participant @bobbrown1]

Martin,

Here's a link to a shed company and their views **LINK**

If it was me and I was insulating a wooden shed then I would do it something like this from outside to inside and if untreated wood, treat the wood on the inside before anything else.

outside wooden wall, air gap 50mm, membrane, insulation 50mm, 1/2" WBP plywood and the same across the ceiling.

You may well need some batten's to space everything but they are cheap enough and you could either use Celotex/Kingspan or my preferred would be Rockwool ProRox SL960 comes in slabs and is very easy to cut with a wood saw. With all the options you will lose some space and will be a bit like a reverse Tardis. If the roof is pitched I would be inclined to fit a vent at the ridge and maybe a couple just above ground level, a small bathroom fan may again be useful in providing ventilation in hot weather or when humidity in the shed is high.

You need to strike a balance with ventilation as the air leaving the building takes heat with it e.g. a shed 6 x 3 x 2.5 with 2 air changes per hour and a temperature differential of say 12 degrees takes about 350 watts of heat with it. I would probably aim at 1 air change/hour and may be use a fan with a humidity sensor.

Others are likely to disagree but my thinking is you do not want a vapour barrier on the walls as this could cause condensation on either side of vapour barrier depending on the temperature differentials and water and wood is not a good thing.

Bob

[Martin KyteParticipant @martinkyte99762]

If you don't want rust you should design for no condensation. To do this the key is ventilation. The building must breathe. Don't make sealed spaces. If you are putting solid insulation on solid walls allow an air gap and ventilate into roof space.

regards Martin

[Bob Brown 1Participant @bobbrown1]

Do not make the mistake of too much ventilation after all it's not a bathroom and all that change of air will need heating in the winter months. From q=m*c*deltaT a shed 3m x 6m x 2.5m with an air change of once per hour then the heat lost from ventilation is about 30watts per hour per degree C so if the outside temp is 0 and internal is 16 then you need to input 480watts.

May be a fan with humidity control on it like this one **LINK** which can be set to start at 60% humidity and off at 50% or a remote switch. On a cold day when you heat the air coming into the shed the relative humidity will drop it is only as the place cools does it go up as the air reaches it's dew point water will drop out.

Bob

[BazyleParticipant @bazyle]

I wonder if Bob the Builder cartoon character could do a video on "Bob insulates his shed". Then every kid would know what to do and every parent too as their offspring watched it for the 50th time

At secondary school please write out fifty times:

"A totally water, air, moisture, vapour and bug proof layer must be put on the inside (room side) of the insulation".

A drip proof vapour permeable barrier may be put on the outside of the insulation.

In non-UK climates where airconditionng is used the requirements may be reversed.

Meanwhile I have collected the parts for the heat exchanger for my eventual shed ventillation system. Incoming air through a 12ft x 2in dia aluminium tube ex TV arial support running coaxially down a 4 in plasitic drainpipe which carries the outgoing air. The fan will be throttled to set only a few degrees loss between in and out.going air. This will have valves to shut it off when unoccupied since the aim is such good airtightness that the space can be pressurised.

The more expensive solid insulation like Kingspan and Celotex is 1.5x to 2x better than rockwool.

Use wire mesh over ventillation holes to keep mice and wasps out .

[Oompa LumpaParticipant @oompalumpa34302]

"The more expensive solid insulation like Kingspan and Celotex is 1.5x to 2x better than rockwool."

I had a good friend, Gordon Winstanley, recount one of his tales of a night out on the Town in the early seventies. He was an apprentice on a building site at the time and on the way home after a particularly raucous evening he was staggering past the building site the thought occurred to him that he could get into the stores and lay down for a while "until he felt better".

He woke sometime during next morning on fire. He had made a bed from and curled up in a bed of Rockwool

graham.

[NJHParticipant @njh]

Well David

I have been following this thread with increasing dismay!

This must be one of the longest answers ever on how to remove your garage door and convert the space into a workshop! I do hope that you have learned something from it – even if you now think it better that you take up stick wittlin' or embroidery instead of model engineering! However – you are now armed with some information on the delights that await you should you decide to make modifications to your new property which do require the scrutiny of the planning department.

Good Luck!

Norman

[Mark CParticipant @markc]

"stick wittlin' or embroidery " – Norman, have you any idea how dangerous these pass times are? Health and safety would have you away in double time for messing with sticks (parents don't tell their kids about removing eyes with sharp things for nothing you know).

Mark

[NJHParticipant @njh]

Mark

Yes, of course that's true. Do not however discount the dangers of embroidery. My wife is an expert and enthusiastic needlewoman – knitting, sewing, patchwork, quilting, embroidery are all her "thing". When in our house never underestimate the risk of walking across the carpet without your slippers….. and encountering a rogue needle !!!******!!!!

( It's not so much the entry that hurts — much worse is pulling it out !!)

Norman

Edited By NJH on 23/04/2014 23:53:20

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