Raft & Foundation

vanman99

Anyone know how long it would take to put in the raft and foundation for a 2300 Sq m house.

Johnnyhpipe

Raft and foundation? A raft is a foundation.. Do you mean a raft foundation? Is it piled? Do you mean strip foundations and a ground bearing slab?

Metric Tensor

Hi OP. The foundation work normally goes hand in hand with the site clearance works, entrance roadway, etc.

So you need to redefine your question first. Do you mean how long after starting work on a green field site will I have my foundation complete it do you mean how long the put in a foundation after the site is fully stripped and excavated to a suitable bearing depth for the fill beneath the raft foundation?

Either way, sadly, it is an almost impossible question go answer because it depends on both the weather and the possibility of unforeseen ground conditions. Also are you doing in direct labour or is a contractor doing it for you? This will also affect the timeline.

If you just have a green field site now and assuming your commencement notice has been lodged and accepted two weeks ago then you should probably budget a month to two months to have the foundation poured. Bear in mind that concrete required curing time after pouring to gain strength.

vanman99

Thanks, yes, i'm a doughnut....Raft being the foundation, so how long after starting work on a green field site will it take to pour the raft after the site is fully stripped and excavated to a suitable bearing depth for the fill beneath the raft foundation?

Assuming weather and ground conditions are perfect wondering how long it normally takes.

Thanks,

Damian

Metric Tensor

If the fill is in and compacted (don't forget the radon sump and pipes!) then it's mounds, radon barrier, boards and steel fixing prior to a one day pour.

All that could be done in a couple of weeks depending on how many lads are steel fixing. Like I said though - only a contractor will be able to mobilise the labour and materials that fast. If you are doing it direct labour it will take a lot longer.

NB - Your engineer will require 2 to 3 visits to inspect the ground conditions, steel, etc during this period. Make sure you have him all set up.

mjp

Will be pouring raft foundation next week. Have blocklayer ready for whenever I want to give him go ahead. How long should I leave the raft before go laying any blocks?

Johnnyhpipe

mjp wrote: »

Will be pouring raft foundation next week. Have blocklayer ready for whenever I want to give him go ahead. How long should I leave the raft before go laying any blocks?

The only person who can answer that is the design engineer.

kun aguero

28 days technically. F
To allow the concrete to reach its design strength.

In most cases it reaches it after 10-14 days depending on the mix itself, but you are safer waiting the 28 days. Also, it gives time to allow the raft settle its weight better onto the hardcore before blocklaying

normanbond

Johnnyhpipe wrote: »

The only person who can answer that is the design engineer.

Hope much (approximately ) can I expect to pay the design engineer to draw up raft foundation and piling plan?
....I have an architect overseeing and signing off on the build so I need an engineer on this item.

Gumbo

normanbond wrote: »

Hope much (approximately ) can I expect to pay the design engineer to draw up raft foundation and piling plan?
....I have an architect overseeing and signing off on the build so I need an engineer on this item.

You will also need an Engineer for the wall structure, any structural beams and possible roof construction.