Thread: Dividing a shed

Your plans for insulation and soundproofing are good. Just remember that the optimal figures they give for noise reduction relies on an entire system, not just the insulation. There may be marginal benefit in using r2 soundchek batts over ordinary r2 insulation batts. I considered it for my shed, but ended up using normal R1.5 batts and the sound attenuation is adequate. If there's a roller or panel lift door in the workshop side you'll have a lot of sound leakage through that, so you may not see the benefit from acoustic grade insulation.

As for the cladding, if you use French cleats then these should be fixed into the stud framing, so the load bearing capacity of the lining isn't crucial. A dense material like fibre cement sheeting will provide better sound control, and is more dimensionally stable than plywood. It's also a lot cheaper, 6mm villaboard is less than half the cost of 12mm birch ply. If you're doing plasterboard on the office side, then FC on the workshop side is sensible, set the joins and paint the same way. Any lining you use needs to have setback from corners and gaps to allow for movement/expansion. I allow 2mm between ply sheets.

Another option is to use slatwall sheets. I might be a bit biased here because I've used it in my workshop - Down the rabbit hole… shed refurb - but it's 16-18mm melamine mdf which gives good acoustic performance and plenty of options for hanging from it. I bought enough of it used out of a retail shop being remodelled to line most of my 10x7 metre shed for just $150. Being melamine it cleaned up like new with some meths on a rag. Brand new sheets are around $130 or so, depending on where you source it from.

If the shed has any sort of breeze blowing past this will generate slight vacuums inside the two partitions. If it creates more of a vacuum on the NWS of the shed, then dust will move from the WS to the NWS.

Sealing is a good start but you may want to force the issue by making the WS side more leaky so this will generate a greater vacuum inside the WS than the NWS. This can be done by leaving a window slightly open on the NWS.

More importantly is to make sure there is a pressure differential while the dust is being made on the WS. Locating or venting the DC outside will automatically generate a greater Vacuum inside the WS.

If you really want to force the issue of creating a pressure differential between the two spaced you could even slightly over pressure the NWS by use of a bathroom exhaust fan to drive clean air into the NWS. The exhaust fan could be wired to come on when the DC comes on.

Then it becomes critical where the exhaust fan and DC are located.

Is is a stand alone shed?

Thank you for the thoughts to date!

Good ideas, and much food for thought

@richmond88 - thank you for the tip on the cleat mounting - it's starting to sound like it might be a good idea to build a medium size timber frame, attach that to the metal dividing wall structure, and then use it to mount the lining on the dividing wall, and it'll then provide a stuf structure to hang stuff from. I was looking at Birch Ply mainly for the looks, and hoping I might get away with 6mm stuff - for dust penetration this should be adequate, and especially if I mount the stuff on a frame, it'll provide the structure for French cleats - and I like the look of birch...

@BobL - thank you for your thoughts! To answer, it is a stand alone shed, and I was planning on the dust extractor being on the back wall of the shed in its own structure - my only doubt about that is that it's right near a vegetable garden, and I'm wondering if the dust there will harm the veggies... all doors are on other walls of the shed, as are all windows except one - it's 5m away from the DC location though, and is a normally closed window (it can open, but it's there for natural light and the view only). In terms of DC I was considering this one: https://www.timbecon.com.au/extracti...dust-extractor - it needs to handle a table saw, band saw, and planer/thicknesser (individually, not all at once), but they're located a few metres away from where the DC will be installed, so I was planning on 6" PVC around the ceiling level, dropping down to each machine as required with permanent PVC as far as I can go, then using flexi duct to reach the final bit (the machines need to be mobile as space is a premium).

Most of the very fine dust that exits a DC enclosure is usually warmer than the surround air so it floats away like warm air. If your DC leaks they will usually deposit any career dust inside the enclosure. Dust can always be washed off vegetables. if its clean dust you can use it as compost.

The rest of your dust plan sounds good to me.

Thank you Bob!

I actually just went and looked at the specs on the machine, and I think I got it confused with another - given that it has an 8" input port, would the smart choice be to use 8" PVC around the shed as far as possible, and then try to modify ports on the devices to accept as large as possible up to 8"? I'm wondering if 8" ducting is too large?

Originally Posted by Midnight Man

Thank you Bob!
I actually just went and looked at the specs on the machine, and I think I got it confused with another - given that it has an 8" input port, would the smart choice be to use 8" PVC around the shed as far as possible, and then try to modify ports on the devices to accept as large as possible up to 8"? I'm wondering if 8" ducting is too large?

I'd be taking the machine specs with a few gains of salt.

If you can find 8" PVC ducting then please let me know as I have never been able to find it - well not at any sort of reasonable price.
You can get 8" metal ducting but make sure you are sitting down when they tell you the price.

Whatever you use you really need the air inside the dust to be travelling at >4000 FPM so any sawdust does not settle out of suspension
This translates to ~1400 CFM in an 8" duct = that's minimum and you really need to start out with more because its all down hill from there in the real world.

Once that Timbecon DC has conditioned filters, a real ducting system and basic machinery connected to it I don't reckon it will even pull 1200 CFM let alone 1400 CFM.

The nearest in PVC to 8" that is not going to tear holes in your wallet is 240 mm (9.45") ID - this requires about 1900 CFM to meet the 4000 FPM criterial.
This is ClearVue max territory.

There are very few machines (e.g. big drum sanders) that can transfer 1400 CFM though them as they are so choked up.
It's not just a matter of opening up the dust port on a machine you have to let air into a machine so you will have to apply some radical metal surgery to machinery.

This is why 6" PVC seems to be the best all round deal. If you have the $$ to go with metal ducting then 7" ducting would be about the best.

If the DC is up for it then 6' ducting can readily transfer >1000 CFM which translates to ~5600 fpm which is well above stall speed for sawdust in a duct.

6" ducting and a 3HP machine is OK for sheds up to about 35-50 square m - beyond that shed size a larger DC will be needed because the ducting runs start to get too long for efficient dust extraction.

Thank you for the valuable insight Bob - it sounds very much like I will stick to my original plan then! And good to know the "coverage" area, I have about 27sqm, in an L shape, so that is sounding all very positive!

Back to the shed design

I think I'd be lining the dividing wall on the workshop side with Firecheck or similar to create a fire barrier between the shed and the office, in case something in the shed goes really pear shaped.

Also like BobL's idea of positive over pressure within the office, or negative pressure within the workshop. Remember hand sanding can produce copious quantities of fine dust.

Originally Posted by ian

I think I'd be lining the dividing wall on the workshop side with Firecheck or similar to create a fire barrier between the shed and the office

Ian - thank you, that is something I hadn't considered, and it's a really really smart idea! Many thanks for the thought!

A quick Google has bought me to this: https://www.plasterproducts.com.au/p...m-fire-check-0 - is that what you were thinking of please?

Yes, that is what I was thinking of.

I think there is also a fibre cement sheeting that is similarly fire rated.