Rod System

[MortarThePoint]

Another thread (link below) made me wonder about simple garden room foundations. This led me to discover the Rod System which looks interesting. Does anyone have any experience of the long term stability. The rods are concreted into the ground and don't go very deep so that makes me wonder. The loading won't be high, but would be interesting to know. Could be made adjustable for later correcting any movement but that doesn't appear to be done.

 

In the US, you often see people using Sonotubes which are e.g. 12" cardboard tubes put into an augered hole and filled with concrete. These can go much deeper, but could still have a rod system at the top, though that's not how the US guys seem to do it. They have the tube/concrete stick out above grade and then bracket or bolt the timber directly to the concrete. It's cheap to hire an auger machine in the US due to how common this approach is (e.g. for decks).

 

Flexible approach:

 

 

Example of fitting timber base onto rods:

 

 

Close up of parts:

 

 

Another example:

 

Sonotubes:

 

 

 

[SteamyTea]

My cheap, timber, shed just sits on some old paving slabs and bricks. Been like that for at least 15 years.

Think it really comes down to what you do on the floor i.e. gym equipment or light engineering.

I just store shit in my shed, and last night, the neighbour's cat.

[Temp]

The purpose of foundations is to spread the load of the building over an area that the ground can support.  Oh and be tolerant of things that might mess with that like tree roots and water. Just about any system that achieved this should be fine.

 

With the rod system just make sure you can't trip over and impale yourself. I had a narrow escape with some hold down bolts.

[MortarThePoint]

You can get a funny looking spread base for Sonotubes as well:

 

 

 

Metal music not mandatory 

 

[Jadhacha]

Liam’s a legend, his Facebook group is great too. He makes building garden rooms look ridiculously easy. I’ve bought one of his build pack as a thank you, no plans to use it. 
 

But mostly timber and insulated metal SIP panel builds. There are 100’s if not 1000’s who’ve using the ‘rod’ system to build off of. 

 

 

10 hours ago, MortarThePoint said:

Another thread (link below) made me wonder about simple garden room foundations. This led me to discover the Rod System which looks interesting. Does anyone have any experience of the long term stability. The rods are concreted into the ground and don't go very deep so that makes me wonder. The loading won't be high, but would be interesting to know. Could be made adjustable for later correcting any movement but that doesn't appear to be done.

 

In the US, you often see people using Sonotubes which are e.g. 12" cardboard tubes put into an augered hole and filled with concrete. These can go much deeper, but could still have a rod system at the top, though that's not how the US guys seem to do it. They have the tube/concrete stick out above grade and then bracket or bolt the timber directly to the concrete. It's cheap to hire an auger machine in the US due to how common this approach is (e.g. for decks).

 

Flexible approach:

 

 

Example of fitting timber base onto rods:

 

 

Close up of parts:

 

 

Another example:

 

Sonotubes:

 

 

 

 

[MortarThePoint]

On 30/07/2025 at 20:52, Jadhacha said:

There are 100’s if not 1000’s who’ve using the ‘rod’ system to build off of. 

 

It looks like a great approach for lightweight buildings like garden offices. I'd want the load spread a bit more than they appear to though. Looks like tops 200mm diameter hole every 1.2m which makes for a pressure of (1.2m*1.2m*1.5kN/M2) / (3.14*0.1m*0.1m) = 69kPa

Which I expect would high to bear in the alluvium