Can you build a shed on a Bessa block base?

[sara22au]

Im going to shortly be building my shed on a large moderately sloping block in the Blue Mountains, where winds can be fierce at times. Since a concrete slab is too hard to pump to, and pavers aren't really an option due to water run off, I was wondering if there's any reason I can't do this-

Create a base using bessa blocks for the base frame, with a sub soil drain in front for water diversion, and also using bessa blocks internally to create a cross flooring frame. So, the frame would sit on the levelled edges of the bessa blocks and be secured to those, and interior would use the bessa blocks plus a cross frame for either a metal floor, or marine board with waterproofing underneath.

Is there any reason this isn't viable?

Cheers😁

[Jewelleryrescue]

Hi @sara22au 

By  all means install a besser block floor but it is only the individual besser blocks that will anchor the sides down Cement filled would make them stronger. The besser in the middle are just  flooring accessories and wont add to wall strength, And Besser blocks on their sides have 30 to 40 mm concrete walls realativy weak against repeated wind gusts that  can shatter  at individul anchor points in the bricks if that is  what you are thinking.

Or.

Consider using super strong  Metal  strapping laid under the heavy besser floor like a metal basket  the wind will have to lift shed and most of the bessers before it budges as well as still fixing sides to besser edging blocks .  

Abey 30mm x 0.8mm x 30m Galvanised Punched Strapping I/N: 1093242

$55.46

Use the Strapping laid under the besser  floor like  basket weave going north to south.  east to west  Or  even diagonally  at least 4 straps alinged maybe with the sheds posts for strength (not onto metal sheeting ) and  have  at least 400mm  coming up out of the ground  on the inside of the shed so  it stays pretty on the outside.  

1 plan and lay your straps along the ground  under all the besser allowing for 400mm wall tethers at  each end point.

2 lay your besser floor with or without cement plus drain

3 build your shed walls on the besser floor keeping the straps inside wall.

4 once your shed built use 4 to 5 metal screws  per strap and screw it to shed posts. Strap is flexable so can move to the post.

5 you  still drill into bessers and anchor sheds sides.

The  effect  is the straps if the shed tries to lift will be increasingly wieghed down by more and more bessers across the floor as  the strap pulls  upwards. Naturally 4 straps like this will hold a lot of wind force.

Further  use of the strap:

Put straps across the top of the roof locking the roof panels down front and back to the frame. If any works  panel loosens  the strap wont let it go any roofing fly off any where.

Probably not needed  but run straps inside the roof  frame and down the walls holding roof section to wall section.

All this should give the Three little pigs  Wolf a very bad  day.

To answer your question I dont think wall anchors alone will with stand solid repeated wind abuse  over time.

See If this helps you plans.

[sara22au]

Thanks for the reply, gives me more to think about! Was planning on both sinking rods and filling bessa blocks with concrete ( the shed base frame ones, not the internal ones), and it's good to know that there doesn't seem to be any reasons I can't do that! I'll have to do some research on strapping, and see how that could be incorporated if needed.

Cheers😁

[Jewelleryrescue]

Hi @sara22au 

If you going rods into the  ground  use  star pegs 400mm into the ground at least they are extremly hard to pull out of the ground.  Hammer them in at a 45 degree angle it will triple your wind resistsnce.  Some of them are tar  coated and will last a long time underground.

Merry Xmas

[MitchellMc]

Hi @sara22au,

It's great to see that you've already received a helpful reply from @Jewelleryrescue. I'd agree that a Besser block foundation sounds like it would work, but I wanted to reiterate the need to connect multiple blocks, potentially with strapping or reo, to the frame. I've seen a structure pick up several Besser blocks in high winds like they weren't even there, so running strapping under several of them sounds like good insurance.

Please let us know if you have further questions.

Mitchell

[sara22au]

Thanks for the reply....but I'm now really curious as to what structure went flying with bessa blocks attached lol. We've had trampolines get picked up.and dumped on top of power lines here, but never seen flying bessa blocks! Winds usually peak at 100kmh gusts, which is pretty bad,but I know down the snowies they can reach 140kmh gusts, and I suspect that would def pick up.bessa blocks...

[MitchellMc]

At my home, I had a gazebo tied down to the base of four trees and full-sized Besser blocks, with each leg of the gazebo passing through them @sara22au. The gazebo lifted the four blocks attached to its legs into the air like they weren't even there, and only the ropes stopped it from flying off. That's likely the worst-case scenario; I just didn't want you bolting the shed down in four corners to four blocks and experiencing similar.

Mitchell

[sara22au]

Wow! I'm planning on cementing the bessa blocks into both the ground, and with sunken spikes, plus filling them with cement, so shouldn't have that problem. Have seenany gazebos go flying, even when weighted with 20kg sandbags, so you aren't alone!