Lockdown Project & Stratarise

[BigJock2005]

Since - like many - our summer holidays were all cancelled this year, I had a moment of madness after chatting with a mate and ordered a hot-tub. Was amazed to find a number of retailers out of stock, they are apparently having the best year ever as I'm not the only one with this idea. So much for being an individual...

Anyway, having duly cleared the space in the corner of the lawn of weeds and shrubs, I am setting about building a 5m x 5m deck to accommodate said tub and an adjacent gazebo.

I'm using treated C24 timbers 47 x 150mm for the entire frame, using BCP steel joist hangers, and will space the joists 400mm apart. I'm going to then floor the deck in 18mm construction OSB as it will then be covered with some very nice fake grass. Probably over-engineered, but the tub with 5 people in it could weight 2 tonnes.

I want the deck to float just above the grass. The surface is pretty firm as our substrate is almost all chalk, which you hit with the spade only a few inches down.

Since the deck is low, ideally just almost sitting on the grass, I was thinking about using the following product for levelling the frame directly onto the surface:

https://www.stratarise.co.uk/index.php/products/3560ml-df-pedestals-for-decking-flooring

The spec says they are point load tested to 800kg per unit. If I space then under the tub at 500mm intervals on every joist under the tub, then that will be 30 supports and a (theoretical) combined load capacity of 24,000kg or 24 tonnes!

Has anyone used these units before and have any experience with them? They seem to get only 5* reviews on amazon, but would be good to hear if anyone on here has used them.

Thanks
Jock

 

[Ian H]

I haven’t used those legs so can’t comment but would a concrete slab be better?

Do you know which Hot Tub you are getting?

 

[BigJock2005]

Tubs are getting in very short supply with everyone having the same idea. Summer holiday cancelled? Hot tub staycation.

I went for the Aquatub 100 which is a US-made 13/32A which for me had just the right amount of bells and whistles without being stupid.

Regarding the foundation pads, yes I could put a concrete slab under them, but their selling point is that with a 200mm wide base they can be laid straight onto the substrate, which in my case is just heavy duty weed control sheets laid down after I took the top layer of grass off. As I said, my topsoil is think, and incredibly hard, with the spade hitting chalk within an inch or two, so digging holes for concrete won't be great. When we sunk the foundations for a retaining wall a year ago, Buildings Control wanted an 18" foundation, the builder couldn't get down any further than 9" with a mechanical drill, BC signed off on it basis the continued drilling might damage adjacent houses!