Underlag för utomhusbadkar
Ett utomhusbadkar fyllt med vatten och personer ger en rejäl punktbelastning. Bygg ett underlag som bär vikten, dränerar effektivt och inte sjunker i något hörn.
Varför armering är viktigt här
A filled hot tub commonly exceeds two tonnes, concentrated over a small footprint, and it splashes constantly. That combination destroys bark, slabs on sand and untreated ground. A grid base spreads the load across the full area and lets splash-out drain away instead of pooling under the cabinet.
Var detta fungerar bra
Snabböversikt
| Sub-base | 150mm MOT Type 1, compacted in two layers |
|---|---|
| Infill | Angular 10-20mm gravel filled level and blinded |
| Typical loading | Point loads from a filled tub, typically 2 to 4 tonnes over a small footprint |
| Permeability | Fully permeable. Normally treated as a SuDS component in a drainage strategy. |
| Design life | 25 years, subject to documented installation. |
| Material | 100% recycled polypropylene, made in the UK. |
Så här installeras det
- Mark out the area and excavate to the depth of your sub-base plus the grid depth plus your infill blinding.
- Lay a woven geotextile across the formation, lapping joins by at least 300mm. This stops the sub-base and the subsoil mixing.
- Lay and compact the sub-base: 150mm MOT Type 1, compacted in two layers. Compact in layers rather than all at once.
- Blind the sub-base with a thin layer of grit sand and screed it level. This is what gives you a flat finished surface.
- Push-fit the grids together across the area, working from one edge. Cut around obstacles with a jigsaw or fine-tooth saw.
- Fill the cells: Angular 10-20mm gravel filled level and blinded. Work the fill in with a stiff brush so no cell is left hollow.
- Check the finished level. Nothing should stand proud of the cell walls, and no cell should be left under-filled.
Most installations are straightforward groundwork. The grids themselves push-fit together and need no fixings, adhesive or specialist tools.
Vilket gitterdjup?
The 30mm heavy duty grid is the correct choice here. A filled hot tub is a concentrated point load well beyond ordinary garden use, and this is exactly what the heavy duty grid is for.
If you are between two options, take the heavier duty one. The cost difference across a typical project is small next to the cost of lifting and relaying a surface that was under-specified.
Det vanligaste misstaget vi ser
Underestimating the filled weight. People size the base for the empty tub they collected on a trailer, not the loaded one with four people in it.
Vanliga frågor
What sub-base depth do I need?
150mm of compacted MOT Type 1 as a minimum. Hot tubs are far heavier than most people expect once filled.
Does the base need to be perfectly level?
Yes. An unlevel hot tub stresses the shell and can void the manufacturer warranty. Check with a long level in both directions.
Will splash-out drain away?
Yes, that is a key advantage. The surface is fully permeable, so water goes straight down rather than sitting under the cabinet.
Can I run the electrics under it?
Run the supply in ducting beneath the sub-base before you lay the grids, and have it terminated by a qualified electrician.
How far past the tub should the base extend?
At least 300mm on all sides, and more on the access side. You need somewhere dry to stand while lifting the cover.
Does the base need a fall on it?
No. The surface is permeable, so water goes down rather than across. Build it level for the tub.
Fråga vår ingenjör
Frågor om djup, bärlager, kantsten eller vilket system som passar ditt projekt? Ställ dem nedan.