Foundation types - Jackpad vs. concrete vs. screw piles

Hello everybody, let me show you my direction of a concrete interface between Trench foundation and End/combo frame…just an idea. There is a simple shape-model with 4 cylinders on a concrete square pad which hold/fix a bit combos boards, link: Sketchfab 3D model

There is a jackpad solution link:

Helical screw piles solution, ok, but how to connect it to the “End” module of the “Floor” module?
We have prepared such 3D model with screw piles interface, see link:

But when combos will be omitted, how do you plan to somehow connect the floor/end to the ground???
If you have any similar/different solutions how to solve this details/interfaces, it would be great to see. Please share. Thx

note: I do not know how to insert pictures in this new community channel :frowning:

1 Like

Hi @jiri_strunc Great question! Thanks for sharing your 3D models too, really helpful.
Previously with combs we have used something similar to your screw pile model but with jackpads attached to a solid timber bearer, and reduced the height of the combs so the bearer sat within the depth of the floor structure. You can see details of this jackpad/comb connection in the garden studio that Phil from Real Living Homes has built: Wikihouse Skylark 200 - Garden Office Timelapse - YouTube

Actually, by removing combs on version 0.2 this is detail gets a lot simpler. You may have noticed that there’s already a notch designed into the Skylark200 v0.2 ground floor beams for 150x150mm timber rails. You also no longer need to work out how to attached the combs to these rails/soleplates, and can just use screws directly through the ends of the Skylark floor beams into the solid timber to hold the structure down.

Jackpads or screw piles can be spaced out along the timber soleplate (around the perimeter of the building footprint) and bolted directly to it. You’ll need to look into specifically what pile caps/heads the jackpads and screw piles come with to fit a 150x150mm beam, and may need to drill your own holes for bolts in them.


Thanks for this both. This is my main question overall - we have a hilly woodland site and ideally I’d like to use screw piles - I find the foundations and attachment aspect massively intimidating as a newcomer to the subject, as with so many aspects of the overall build.

Hi @royhendo I would love to hear more about your project. The attachment part should be pretty straightforward: screws into a beam; beam bolted to pile caps. For small (sub-building regs) structures it just needs to be enough screws to prevent any uplift during strong winds (something like @50mm spacings along the building perimeter would do it). If you’re building something larger or two storeys you’ll be working with a structural engineer who can spec the exact fixing requirments. The screw-pile company should be able to assist you with the right pile caps and spacing of these for the size of the timber bearer you’re putting on top (nominally 150mm square). If you want to chat more about your designs feel free to message me directly :slightly_smiling_face:

Thanks @Clayton I’ll take you up on that. Really appreciate it - I need to find time to take some photos…