ᐅ Drying time for a completed basement before assembling the prefabricated house

Created on: 22 Apr 2024 13:22
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DachDrueber
Hello everyone,
we have received very different statements regarding the drying time of a precast basement during planning for a prefabricated house:

- Extreme 1: A precast basement can be built on two days after installation. Although the concrete only reaches its full strength after 28 days, the main load-bearing parts are already dried and have their design strength beforehand. The residual moisture in the cast transitions can continue to dry out.
Claim: Those who want to allow a long drying time do so only to bridge the long delivery times of the prefabricated house.

- Extreme 2: A precast basement should dry for at least 8-12 weeks to reliably achieve sufficient drying.
Claim: A shorter drying time is only a means to attract customers with shorter construction schedules.

Does anyone have any insights on this?

Thanks!
Y
ypg
22 Apr 2024 20:28
Basically, none of this really matters when it comes to the placement of the house. The manufacturing of the house takes its time, and logistics often involve more than just the net production time. However, builders can usually estimate whether the house can be delivered in 15 or 18 minutes. If you plan to build with a basement, it will be constructed beforehand at some point. Whether a basement cures for 72 hours or 31 days will not significantly affect the placement of the house. One homeowner might think otherwise, but on the other hand, there is a company that aims to satisfy many homeowners. This is only possible with good advance planning.
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filosof
24 Apr 2024 07:49
Setting up the house two days after the basement concrete work might be technically possible. In reality, however, it is hardly feasible. After pouring the concrete, sealing still needs to be done, the ring ground electrode installed, the working space backfilled, and the scaffolding erected. All of this within 48 hours, and then the trucks and crane are already ready – I just don’t believe that.
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filosof
24 Apr 2024 07:59
filosof schrieb:

Setting the house two days after the basement concrete pour might be technically possible. In reality, however, it’s hardly feasible. After pouring the concrete, the waterproofing still needs to be done, the ring grounding system installed, the working area backfilled, and the scaffolding erected. All of this within 48 hours, and then the trucks and crane have to be ready – I don’t believe that...

P.S.: From my own experience, I strongly advise against such a tight schedule. If anything goes wrong during the basement construction causing even a few days’ delay, then the date for setting the house falls through and could be postponed by several weeks or even months until it can be rescheduled. In our case, it rained when the waterproofing was supposed to be done – it wasn’t possible. The crew had to move to another site, and I really had to push hard to get a different team to come and finish it just one week before the house setting date – then the other tasks were carried out (see above), and we barely finished before the crane arrived...

The original plan allowed three weeks between basement and house setting. Today, for purely organizational reasons, I would insist on at least six weeks. Technically, I would rely on the expertise of the general contractor/basement builder. If that competence were not there, I would look for someone else right from the start...
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DachDrueber
6 Jan 2025 11:36
Current status of our basement-house schedule:
(Basement) completion in calendar week 3 (+ beginning of calendar week 4)
House framing: calendar week 7
According to the basement company Glatthaar, this schedule works fine