Questions on how to build a shed mikes way?

[Rob Cheetham]

I am designing and building my own shed/workshop and have been following the layout plan of how to build one mikes way with a concrete slab.

I have just laid the concrete slab a week ago and have now realised that I missed the part where it says to cast l shaped steel straps into the slab to hold the sole plates down to the bricks.

Obviously I cant do this anymore so what would be the best fixings to use to fix the soleplates down into the brick and possibly further into the concrete?

Also on Mikes diagram it says minimum 2 course brick. I have bought enough bricks to start with to do one course. My question is why is minimum 2 course essential. The slab and one course would make the soulplate about 200mm above ground level so im thinking that would be sufficiant to my needs. What are peoples thoughts on this. Im not spending another £80 on bricks if I dont need too.

Thanks again and apprieciate any feedback

 

[matkinitice]

The three courses of bricks is to get the wood up and away from any failing water (rain) that would splash up. It's the same principle in house building. As long as you're ~150mm above ground you should be fine. Anything else would be down to aesthetics. Just remember to have a DPC between the course and your frame - the straps are to prevent you needing to pierce the DPC in order to attach the frame to the plinth.

You can just screw the straps down into either the plinth (what I'm doing next week) or into the concrete. Don't need to worry about casting them into concrete, they are only there to stop the shed blowing up and away. As for the fixings I plan on just drilling holes and using plugs/screws, nothing fancy.

 

[MARK.B.]

yep what he said

 

[Lons]

2 course of bricks is to ensure a minimum 150mm above ground level so as long as you don't build up soil against the concrete that's fine. Have you put a dpm, under the slab? Not essential just belt and braces which comes from my experience as a builder. The only other comment I'd make is that a single course of bricks is weaker than 2 course as there is no bond present so you need to be more careful fixing the soleplate.

 

[Spectric]

You can just screw the straps down into either the plinth (what I'm doing next week) or into the concrete. Don't need to worry about casting them into concrete, they are only there to stop the shed blowing up and away. As for the fixings I plan on just drilling holes and using plugs/screws, nothing fancy.

Build a decent shed and the weight will hold it down, and if you really want to fix it down you could use a building adhesive which is also water proof.

 

[Rob Cheetham]

The three courses of bricks is to get the wood up and away from any failing water (rain) that would splash up. It's the same principle in house building. As long as you're ~150mm above ground you should be fine. Anything else would be down to aesthetics. Just remember to have a DPC between the course and your frame - the straps are to prevent you needing to pierce the DPC in order to attach the frame to the plinth.

You can just screw the straps down into either the plinth (what I'm doing next week) or into the concrete. Don't need to worry about casting them into concrete, they are only there to stop the shed blowing up and away. As for the fixings I plan on just drilling holes and using plugs/screws, nothing fancy.

Thanks for your reply. Yes I will be above 150mm so think ill be fine. Will be putting in a dpc between brick and soleplate too and using treated for the soleplate aswell.

What are these fixing straps actually called as I havent a clue and cant find anything online when I google it. Found hurricane ties but they seem to be for the rafters to the top plate.

2 course of bricks is to ensure a minimum 150mm above ground level so as long as you don't build up soil against the concrete that's fine. Have you put a dpm, under the slab? Not essential just belt and braces which comes from my experience as a builder. The only other comment I'd make is that a single course of bricks is weaker than 2 course as there is no bond present so you need to be more careful fixing the soleplate.

Think I should be ok with one course then other than being weaker than 2 but think ill be ok.

Also yes I have put a 1200 dpm under the slab with a 100mm hardcore base and then roughly 120mm slab throughout 18x11

 

[Rob Cheetham]

Build a decent shed and the weight will hold it down, and if you really want to fix it down you could use a building adhesive which is also water proof.

What buidling adhesive would you reccomend and would this just go on top of the brick then stick the soleplate down to it while putting in some fixings aswell at the same time?

 

[TheTiddles]

What buidling adhesive would you reccomend and would this just go on top of the brick then stick the soleplate down to it while putting in some fixings aswell at the same time?

I think he’s joking Rob, I mean, I hope he is...

 

[matkinitice]

The weight alone of the framing and sheathing should be good enough, but the straps are a belt and braces approach. I wouldn't use adhesive. In fact I'm sure in one of the build threads here someone admitted to forgetting this step and not actually screwing in the straps and years later everything is fine - but it's such an easy thing to do and gives you peace of mind.

Something like this is what I have purchased: Sabrefix Builders Band Galvanised DX275 9.6m x 20mm

 

[Spectric]

A good adhesive is Sika flex EBT Sika Sikaflex EBT+ Polyurethane Sealant & Adhesive Sealants Online -

Once you stick the wood to the course of bricks and it has set, you could lift the bricks up by the wood as it sticks and seals very well. It is also paintable, but not an issue for this application.

 

[TheTiddles]

I think the lifting of the bricks is the bit that’s desirable not to happen, hence using straps that are happy in tension whereas mortar isn’t.

I just did a quick calculation on wind loads on a shed, interesting, it’s way more force than I expected

Aidan

 

[Fergie 307]

Screwfix and others sell bolts that screw directly into a hole in concrete. They have a hardened thread that actually cuts a thread in the concrete. Advantage is no expansion so you can use them near edges without the risk of cracking. Can't see why you couldn't use an appropriate size in bricks. I use the all the time and they are excellent. You only need put in one every three or four feet.

 

[Inspector]

To anchor stuff to cured concrete expansion bolts work really well. There is another type where epoxy is put in the hole with the bolt paced in to cure.

Since before I was a kid in Vancouver houses without in ground basements are often made with a footing 2 or 3 feet down onto undisturbed soil and foundation wall poured at the same time. The finished wall being 1 or 2 feet above grade. Then the floor is poured inside after all the forms come off and often after most of the house is built. The footings were made with 2x6 to 2x10 held a couple feet apart by stakes and 1x2 or 1x3 across the top every 3 or 4 feet. The rented wall forms of plywood are placed on top of the 1x pieces and a 2x4 nailed along the bottom into the 1x to keep the forms in place. They are spaced with special straps (snap ties) that are knocked off with a hammer after the pour is cured. The concrete is poured into the top of the forms and worked a little to fill the footings at the same time. The top is troweled level and hooked threaded rods inserted into the wet concrete as needed to bolt the sill/cill plates to. When the cured the forms are removed and the 1x bits broken off enough to get the footing forms off. What remains is buried (no termites there to worry about) and covered after the foundation walls are waterproofed, drain rock, drain pipes placed against the outside of the footings and backfilled with soil. The advantage is the speed at which one is ready from starting the forms to pulling them off and building walls on top is less than a week for a crew of 2 or 3. No bricks involved and the wall you build on is 6 to 10 inches thick depending on the structure on top. If a wood floor is planned then the floor is built on top of the foundation followed by walls. I understand the slab and bricks are the way you have always done it but there are better options.

Pete

 

[Rob Cheetham]

The weight alone of the framing and sheathing should be good enough, but the straps are a belt and braces approach. I wouldn't use adhesive. In fact I'm sure in one of the build threads here someone admitted to forgetting this step and not actually screwing in the straps and years later everything is fine - but it's such an easy thing to do and gives you peace of mind.

Something like this is what I have purchased: Sabrefix Builders Band Galvanised DX275 9.6m x 20mm

May sound a stupid question but how would I go about applying this band. First time I've heard of these as I'm just a diyer lol.

I take it you cut bits to suit size needed with a angle grinder mayby. Then would I just strap it over the soleplate and brick and fix into the concrete either side to keep it down with concrete screws/bolts

Am I right or is there another way to use these for my intended purpose.

Cheers

 

[TheTiddles]

You can buy pre-cut strips or use “builder’s band” of the correct size