Jimmy Mack's 'Shop Build (photos & video)

[Jimmy Mack]

I'd go for a grinder just for simplicity, but I'm sure someone else might have a more elegant method! Getting the frame up must be a good feeling!

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Absolutely Crispy, a good feeling, especially after all the niggles with the foundations and preparations... the floor and walls have been really snappy... a good moral booster too!

 

[Jimmy Mack]

Got the other side walls up yesterday ...There are some cripple studs and a lintel/header for the door opening to do.




The BCO is suppose to be checking on the walls going up at some point...I was keen to get the walls on the sole plates / mud cills as they look a little ugly where the timber has detached itself from the cement (probably due to all the warm weather moving the boards around) It's a little un-nerving - but I hope, once under load, all will be ok) :eusa-pray:

Rain has stopped play today...tomorrow I'll move on to the front wall and the windows and main door openings.


ROOF & RAFTERS

The ridge beam arrives next week...so today I'm going to look at the rafters. Now... I have NO idea or any experience in this dept. I've taken some measurements and put together a drawing.



I'm in two minds whether to draw a full size rod out on the deck -OR- actually try and figure it all out, I have a speed square (in a drawer somewhere ) - you can all have a good laugh at me - but it all seems a bit of a dark art to my peanut! :?

A note regarding the roof is that I would like to have a slight over hang at the gables, perhaps 400mm. Like in the original drawings (below)





There's not one illustrated - but will I need to design in a gable ladder? -OR- do I just over shoot with my wall plates?

...Gah!...

which makes me now realise I may have goofed as my side walls over lap my front and rear walls - so the planted wall plate won't overlap tie the walls if it has to over shoot :eusa-doh: I think I was too busy trying to over lap my sole plates / mud sill - which then, in hind sight overlaps the wrong way also! (balls)

Can I fix this tie issue with some GMS straps on top of the walls?

Time for a strong coffee and rafter layout videos...

Cheers Jim

 

[Jimmy Mack]

The front walls are fixable if I trim them back with the hand saw...

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[Tusses]

too late now .. but for anyone else doing similar .. under floor insulation would add to the overall comfort in the winter

 

[Jimmy Mack]

too late now .. but for anyone else doing similar .. under floor insulation would add to the overall comfort in the winter

It's a lightly fixed, TEMPORARY deck, to frame off. Once I'm watertight I'll lift it to put in acoustic wool slabs (e.g...Rockwool) which.... as it's currently lashing it down with rain would be all soggy by now!

I've gone for the acoustic as right now it's like a drum skin!

There's also some ducting and cable running to go in too...

Cheers, Jim

 

[Tusses]

ah ok .. but when you get the carpet down it will make a huge difference to the sound level :lol:

 

[Pinch]

NIce to see a bit of woody stuff going on.

It's wood Jim, but not as we know it. :lol:

I couldn't resist that one.

Very nice work matey and it's coming on very well.

 

[Mike G]

Jim,

I'm pretty sure your support for the ridge beam shouldn't be as you have shown it. The 3 posts should be continuous to the sole plate. As it stands, you could have shrinkage across your wall plates, or poorly fitting joints, and that would leave your ridge beam teetering on one piece of timber. Not that it could ever fall off sideways.......the real problem is that this puts a point load into your sole plate and plinth on a very small surface area. I'm sure your engineer (and therefore the BCO) would expect to see 3 continuous studs from sole plate to ridge.

 

[Jimmy Mack]

Jim,

The 3 posts should be continuous to the sole plate

D'oh...It's that darn Yorkshire thriftiness messing me up again!

Amended...



...when I get up there I'll clamp flush and pin them together. Thank you for the correction

Do you have an opinion on my top wall plate points?

• Overlap issue
• Does it over-run to catch a final rafter and create a roof overhang at the gable? (350-400mm)

Thanks again,

Jim

 

[Mike G]

You could overhang the plates, but a properly made gable-ladder doesn't need the support (run your ridge through, though, that helps). 300/400mm is a hell of an overhang. It won't look great.

It's always preferable to have the wall plate run to the end of the building so that all rafters sit on the same piece of timber. However, with an accurate frame, it isn't critical.

How wide is your glulam? I ask, because running your rafters just to the side of the glulam could leave too big a gap to be covered by a ridge-tile, if the glulam is quite wide. You would then have to build up on top of the glulam. The alternative is to notch the top end of your rafters over the glulam.

 

[Jimmy Mack]

The glulam is 140mm

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[Mike G]

What are you putting on the roof? At 20 degrees, your options are limited.

 

[Jimmy Mack]

Cembrit Jutland....I believe they can tile as low as 15 deg

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[Mike G]

OK, a man-made slate. So, you will need an orthodox ridge tile. They're generally around 230 across the base, which means less than a 40mm lap over the tops of the uppermost tiles. Personally, I'd like to see more than this, so if it were me, I would at least consider notching by rafters over the top of the ridge beam.

 

[Jimmy Mack]

OK, a man-made slate. So, you will need an orthodox ridge tile. They're generally around 230 across the base, which means less than a 40mm lap over the tops of the uppermost tiles. Personally, I'd like to see more than this, so if it were me, I would at least consider notching by rafters over the top of the ridge beam.

Thanks Mike - I'd like to avoid any additional notching if possible.

Spoke to Cembrit - they think I'll be fine. If needed they have a Universal Ridge Tile which provides 300mm cover...It was the end of the day so technical are going to confirm on the Standard Tile tomorrow.


Got the front up today and some headers in for the windows and doors. Blocking, wall plates and gable infills to get out of my now diminished pile of 6x2's its amazing how 400m just goes!

It's looking tight....but Hopefully I've enough timber left! :eusa-pray:





Cheers,

Jim

 

[Rod]

Looking nice and tidy

Rod

 

[Crispylettuce]

Jimmy, what are your cladding your shop with? I was just wondering if you were doing something like cement Weatherboards for the areas that will be a pain to paint/repaint?

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[Jimmy Mack]

Hi Crispy, I'm cladding in a vertical profile WR Cedar, 6 cu/m has been sitting on my drive since last June, actually before I got planning! It came up at auction, so took a gamble.

Cheers Jim.

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[Rod]

Cedar - I love the way it ages - great choice.

Rod

 

[Jimmy Mack]

Spent the morning fixing things off, and getting the wall plate up...I'll trim them a bit Mike, promise, not really sure what I'm doing here [emoji4]

Then....


Block,block,block,block.... times a million

....absolutely mind numbing!

Then one of the building inspectors (the one that matters) came out to check with her safety boots on [GRINNING FACE WITH SMILING EYES]

Pretty much all done in the lower frames. Roof fun next week...TBH a bit nervous about goofing this bit, Cembrit are sending me a sample of the ridge tile.

Have a good weekend chaps.

Some arty shots...

Cheers, Jim.


PS. Cheers Rod, I like cedar too... I'm wanting it to age up nice and blend in with the garden.


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[Jimmy Mack]

Skylights (velux types).

I'm wondering about the UV impact on woodworking....The boss wants 4 as per the design, two on either pitch. This will let a LOT of additional light in as the front windows will generally be in the shade.

I'm not sure if ether it might be more sensible to have just two on one pitch and if this should be the south or north facing pitch...or ...perhaps none at all and put some good quality daylight bulbs in!

What do folk think about this? Is it much of an issue?

Jim

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[Mike G]

I think the pluses include lots of good natural light and additional ventilation for those steamy sultry Yorkshire days when it's too hot to think ( ), and the negatives include their cost, the heat loss through them compared with the adjacent insulated roof, the security risk, and the difficulty of accessing them for cleaning and replacing the glazing units. With quite a deep plan, such as yours, your windows won't be lighting much of your floor area, so rooflights would certainly get some natural light into the gloomier corners which you'll otherwise have.

If you were to omit some of them, consider keeping those that you can see from the house, so you could tell at a glance whether you had left them open, and so that you wouldn't have hidden ones which a thief could smash without anyone seeing.

 

[Crispylettuce]

To get around any security concerns, couldn't you use a fixed skylight like this...

.... Granted, I have no idea about cost of something like this vs a velux window.

Has anyone got any experience with anything like this?


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[Tusses]

or laminated glass ?
metal bars would be easy to fit too.

I do think roof lights are a good idea, for light heat and ventilation.
Add blinds if needs be.

 

[Crispylettuce]

There must be a cost effective version without using typical "loft conversion" velux windows.

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[RogerS]

I'd be surprised if anything you were working on would be in there long enough to be affected by UV light.

 

[Jimmy Mack]

Yes, you'd think so crispy...unless I'm looking in the wrong places...windows that don't open appear more expensive!

Perhaps a supply and demand thing. Once you factor in the flashing kit it's around £200-220 per roof window...

Might fit some bars as tusses suggests, Veluxs are apparently easy to break into (without breaking the glass). So not unusual to hear of folk screwing them shut!...an opener might be nice for the hot Yorkshire summers [GRINNING FACE WITH SMILING EYES]


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[TrimTheKing]

I will be, and would heartily advise you to, fitting an alarm system in and around my workshop and not taking any chances. While you have channels dug in the ground for cabling what some Cat5 etc back to the house and fit yourself a few camera's, bell box, internal sounder and SMS alerting. All reasonably priced nowadays and MUCH more pleasing than having to deal with a break in and the loss that incurs…

That would negate all concerns about Velux security as far as I'm concerned because if you have them alarmed along with PIR's then anyone having a go will soon be scared off by the noise.

Cheers
Mark

 

[Jimmy Mack]

I will be, and would heartily advise you to, fitting an alarm system in and around my workshop and not taking any chances. While you have channels dug in the ground for cabling what some Cat5 etc back to the house and fit yourself a few camera's, bell box, internal sounder and SMS alerting. All reasonably priced nowadays and MUCH more pleasing than having to deal with a break in and the loss that incurs…

That would negate all concerns about Velux security as far as I'm concerned because if you have them alarmed along with PIR's then anyone having a go will soon be scared off by the noise.

Cheers
Mark

Cheers Mark Absolutely, I've the duct in and about 250m of CAT6 ready to run as many lengths as possible back to mission control

I'm thinking:


• CCTV
• Alarm
• Doorbell from roadside deliveries etc
• Wifi for media and intercom with the house

What else? Heating control

Cheers Jim

 

[Jimmy Mack]

Spending most of today researching and buying materials...It's amazing how time consuming this is!

We've decided to go with just two roof lights. So they'll go on the South facing pitch. Partly due to the expense and that I'll need the £'s for 22 sheets of Fire Case F (@£30 per 8x4!) for the external fire protection, plus the application of a retardant to the cladding... Don't quite get why I need both...tried to see if I could drop the Fire Case F...but the man from building-control-monté... he say... 'NO'

Roughly layed out my rafters to get my lengths , I get these on Thursday now, so I'll have to find some other bits to work on in the meantime...perhaps chop out and adjust the brick work for the back door and work on the doors and windows. All being well I hope to get the rafters cut Thurs/Fri and the ridge beam up on SAT.

My plan (feel free to comment) on the installation of the beam is to shove it up the garden with a friends mini fork lift, with one end on a dolly, once on the deck...I'll have one north pitch gable rafter up at one end and one south pitch rafter at the other end (i.e. open triangles) with vertical bracing and a gusset tying them to the King Post...With a Genie lift, lift and manoeuvre the beam in diagonally, turn it and capture it with the missing gable rafters...finally... get a few rafters in and some diagonal bracing in ASAP!

In other news the ridge tile samples arrived...looks to be ok. I have to say the guys at Cembrit have been great!



Close up with 135 deg ridge tile (ridge beam in pencil)...

 

[Crispylettuce]

What type of roof light did you go for?

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[Jimmy Mack]

What type of roof light did you go for?

Fakro (Velux style) centre pivot

 

[Jimmy Mack]

Roof insulation: this U business is a bit bamboozling!

Back to my architect chappy, he has specified...

"Insulation to comprise 150mm Celotex FR5000 cut between joists with 25mm Celotex FR5000 to underside of joists and 12.5mm plasterboard finish to achieve U value of 0.16 W/sq.m/k"

I had hoped to use a Knauf acoustic wool or RWA45 or something that will knock out some of the potential noise. However it seems to me they won't meet the U values where my rafters are 200mm deep where 50mm of that needs to be airflow clearance.

This all seems a bit extreme for what I'm doing, including the FR5000 (fire rated? £££'s). As an out-building am I under the same regs as a domestic dwelling?

Jim

 

[9fingers]

Amateur gut feel here is that with 50mm rafters every 400/600mm there will be a good acoustic route from inside to out and so addinf intermediate accoustic wadding won't help a great deal.
In my book there are two keys to acoutstic isolation and those are Mass and Mecahnical decoupling from one side to the other. And you will have neither in this roof.

As for FR I just don't know. Your architect might be on a WIBNI (wouldn't it be nice if) and calling up a hi spec because it must be better (?) From my workshop building days (previous PDR scheme) I think the walls had to be 1/2hr or 1hr FR or made from substantially non combustible materials but there was no stipulation on the roof.
I used concrete block walling on the boundary line and OSB and fibrecement slates on the pitched roof.

Bob

 

[Mike G]

Your "architect" has just cut and pasted that note from another job. However, in answer to your question, if the building is big enough to be under the auspices of Building Control (and yours is), then you have to comply with Part L (heat loss). 150mm of mineral wool isn't enough. However, a nice compromise might be 150mm of mineral wool between the rafters, and a sheet of Celotex screwed to the underside of the rafters. How thick this would have to be would need a calculation, but if you ring Kingspan (Insulation) they will do the calculation for you over the phone, and email you the result for Building Control. I would take a rule-of-thumb estimate at 25 to 40mm of Celotex (same stuff as Kingspan) being sufficient.

I can tell you from bitter experience that anything you can do to avoid cutting Celotex in between rafters is worth doing. It's an awful job, and almost impossible to do well. Put mineral wool between (with 50mm gap above) and Celotex below, and you will probably actually have a better job, and it will be a day or two of work rather than a week or two. As a bonus, continuous sheets of Celotex will offer better acoustic control than cutting sheets in between, and mineral wool is much better than the solid boards in this respect too. This is certainly what I would do in your shoes (And look at that........I've just saved you another small fortune! )

 

[Mike G]

Talking of saving you money, Eternit boards might be a better answer for your boundary walls than cementitious boards plus fire retardant paint.

 

[Jimmy Mack]

Amateur gut feel here is that with 50mm rafters every 400/600mm there will be a good acoustic route from inside to out and so addinf intermediate accoustic wadding won't help a great deal.
In my book there are two keys to acoutstic isolation and those are Mass and Mecahnical decoupling from one side to the other. And you will have neither in this roof.

As for FR I just don't know. Your architect might be on a WIBNI (wouldn't it be nice if) and calling up a hi spec because it must be better (?) From my workshop building days (previous PDR scheme) I think the walls had to be 1/2hr or 1hr FR or made from substantially non combustible materials but there was no stipulation on the roof.
I used concrete block walling on the boundary line and OSB and fibrecement slates on the pitched roof.

Bob

Thanks Bob. The way I see it is there are two elements here, sound isolation and sound reduction. Now I don't think I'll be able to achieve sound isolation - that's for sure- that is where the acoustic decoupling comes in, I'd probably have to build a room within a room. :?

My logic on it all is ...by putting a sealed box over all my noise is a start. If I can...

• introduce more mass / density (double plaster ),
• change the shape of the room (sound reflection) through positioning of stuff (timber rack, books, for example),
• add little decoupling at source (rubber feet pads, baffling, etc.) ,
• seal my openings... aquamac 21, sealant at board joins, etc...

...then there's more of a chance to trap or change some those rouge & harsh frequencies before they get to my rafters, studs and beyond!.... these points of telegraph are sandwiched by a stuffed cavity with a now low resonance. In (my) theory the snug fit of the mineral wool or denser RW slab should hopefully mute some of the reverberations traveling through and along the rafters/studs reducing the sound db levels further, not completely, but as low as possible. The 3ph motors will help

WIBNI (wouldn't it be nice if)

Absolutely bang on and as Mike mentions likely an auto fill or 'Copy & Paste'. It looks good if you can wave all the desirable ecological flags/ logos on the website too.

This is the rub on both thermal & acoustic topics...our place of work is insulated but nowhere near to such a low W/m2K ... once you've had the machines running for an hour of so the motors and extractor push the shop temp up and by the afternoon it's 16-17 deg C! (a max working temp IMHO)...with my über insulated build I'll end up baking and it'll either be strip off :shock: -or- open the windows and deafen the squirrels with the thicknesser :eusa-doh: [emoji38]


Cheers, Jim

 

[Jimmy Mack]

However, a nice compromise might be 150mm of mineral wool between the rafters, and a sheet of Celotex screwed to the underside of the rafters. How thick this would have to be would need a calculation, but if you ring Kingspan (Insulation) they will do the calculation for you over the phone, and email you the result for Building Control. I would take a rule-of-thumb estimate at 25 to 40mm of Celotex (same stuff as Kingspan) being sufficient.

Co-incidently I did just this with Knauf this morning...then when you said Kingspan send a calc I called them too and got the calc emailed

Mike, you were close 'ish with 25-40mm...They both suggested 150 mineral wool above with a 65mm or 62.5mm (in the case of Kingspan) below rafter... Both being a PIR laminate board of 12.5 plaster with 50mm insulation .

So ...

...I'm gonna have to knock a few points off you there, Mike. Should even things up a little...

...probably not [emoji38]

Been calling my guy...still want to know why he's spec'd what appears to be a fire rated Celotex...

Hope Bob's right with the....WIBNI

As a side note on 'Workshop Builds'. No-one mentions the amount of research and madness inducing looking for needles, spinning in circles on Google time that is required! The forum's certainly livings upto its 'haven' name. :eusa-clap:

Cheers,

Jim

 

[Mike G]

:lol:

Well, of course I allowed for the fact that mineral wool isn't actually sold in 150 thick rolls: it is 170...... :eusa-whistle:

 

[Jimmy Mack]

Amazing!...After hours of bending my brain and trying to juggle materials to meet U-Values I get through to the architect who essentially says as it's an out-building I don't need to put ANY insulation in!

Thought I best run this past the ticket man...Mr BCO, who said...'Just get what you can in!'

:eusa-dance:

So... I'm going to stick with just the mineral wool and save a fortune removing the PIR Laminate plasterboard from the budget.

Now...A question regarding mineral wool in the walls, will it slump? Can I stop it from slumping. Should I get slabs?

Jim