precast concrete build

[moldy]

Apologies if the wrong forum... and my lack of knowledge

 

Does anyone build one off residential homes with precast concrete? If not why not? Scenario is a 2 storey, 2 bed, 160sqm house.

[scottishjohn]

you mean ICF --or do you mean concrete panels made off site then errected?

[iSelfBuild]

I'm a consultant within the precast concrete market.

 

A joint venture between Milbank and a Beligium company called Danilith looked like it was going to get traction back in 2015 but it never came to full fruition.

 

I know Laing O'Rourke do housing but not sure if they do one-offs, a few other Irish precasters do small housing developments but I have not come across someone doing the full package yet.

 

You could try https://www.mahousebuilders.com/ we supplied them with magnets and shuttering nearly a year ago which I believe was for wall panels. I'm not sure if they do the full package in precast. I think the main issue for one off houses is the structural calculations and the lifting design and production planning for one offs. However I would be happy to supply MA with all the lifting design calculations free of charge for a one off house for you as I'd love to see precast more widely adopted in the house building sector. I think it's better suited for mass production though.

 

 

[Conor]

Pre cast concrete... We use it on reservoirs, pumping stations etc as it can be faster and use less concrete than in-situ, however, I don't think it works on a small, one off scale:

 

Higher transportation costs as normally slabs have to travel further

Need for heavy lifting equipment on site for longer (cost)

Significant H&S risk of handling large, heavy slabs, esp on small sites with small crews.

Slabs can be difficult to align. Movement and expansion needs to be managed - on a small house this would be a nightmare unless using "whole wall" slabs.

Joints need to be caulked /strapped/ jointed etc, not an issue when working with 12x2m slabs, but could be time consuming with smaller, complex pieces.

Minimal scope for tweaking on site, making changes etc.

 

[moldy]

45 minutes ago, scottishjohn said:

you mean ICF --or do you mean concrete panels made off site then errected?

panels made off site then errected

[scottishjohn]

why build that way --whats the attraction?

 

[K78]

1 hour ago, scottishjohn said:

why build that way --whats the attraction?

 

 

The same as the attraction for precast wall panels. 

 

Drop in situ, bolt down. Quick and easy. Prices for wall panels are good too. 

[Dee J]

See a lot of concrete panel builds in the Netherlands. Typically looks like passive slab, precast wall, floor and roof panels (with service conduits included). External insulation, then decorative cladding. Quite what the economics are I don't know but looks to be fast build.

Think some of it might be just a culture/tradition thing. Many southern European countries use a lot of cast in situ stuff... we tend to use pre-fab timberframe +brick cladding. Each system has a very different skill mix, but all seem to produce reasonable builds at not dissimilar prices.

[Jeremy Harris]

The fairly large (900 people) new build office and lab building that formed part of the last programme I managed before I retired used pre-cast internally insulated panels, bolted to a steel and concrete frame. 

 

The advantages were the speed of fitting the pre-cast panels and the guaranteed thermal performance from having panels made under controlled factory conditions.  Another advantage was the very high quality external finish on the panels, which meant not having to apply any other external finishes, just coloured cladding panels in places to break up the look of the large expanse of almost white, smooth concrete.

 

The disadvantage was the need for a lot of heavy haulage and lifting gear on site (but we had two tower cranes already on site and a specially constructed haul road into the site).

 

For a single house I strongly suspect that the cost of transport and lifting the panels into place would be just too high to make it viable.  It would probably work on a medium to large development OK, though.