Safe room- have you built a house or room using ICF?

[Anonymous]

We are building on a lake lot in at the edge of a tornado prone area, so I'm enjoying some light reading on the FEMA website:
https://www.fema.gov/sites/default/files/documents/fema_taking-shelter-from-the-storm_p-320.pdf

Concrete with rebar buildings seem to be the way to go and ICF (insulated concrete form) is one of the systems they discussed. It's all greek to me, anyone have experience?

[Anonymous]

ICFs are a good system but hard to find contractors who use it. Most contractors are tied to using traditional forms that are removed at the end of the pour. ICFs are a pain in the neck to set up and you have to be super careful during the pour. However they stay in place and add a lot of R-value to the structure. You do need to follow specs carefully however and ensure they're covered in something on the exterior before backfill.

[Anonymous]

Anonymous wrote:We are building on a lake lot in at the edge of a tornado prone area, so I'm enjoying some light reading on the FEMA website:
https://www.fema.gov/sites/default/files/documents/fema_taking-shelter-from-the-storm_p-320.pdf

Concrete with rebar buildings seem to be the way to go and ICF (insulated concrete form) is one of the systems they discussed. It's all greek to me, anyone have experience?

When you say "tornado prone" what exactly does that mean? Like, are you statistically likely to experience a tornado on this property based on historical weather and your time at this property (is it your primary home?)?

If it's not something your builder has ever done you might ask yourself why.

[Anonymous]

If your house has a basement just get the builder to pour two interior concrete walls in the corner of the basement that are connected to the foundation. As long as it has no windows it will be very resistant to tornados.

[Anonymous]

Anonymous wrote:ICFs are a good system but hard to find contractors who use it. Most contractors are tied to using traditional forms that are removed at the end of the pour. ICFs are a pain in the neck to set up and you have to be super careful during the pour. However they stay in place and add a lot of R-value to the structure. You do need to follow specs carefully however and ensure they're covered in something on the exterior before backfill.

I found a contractor who has five years doing ICF and was a concrete contractor before that, not sure if that's enough experience. I have a request out for references for him.

Do you know how much it adds to the cost? And also about curing? A pro/con one builder gave was that concrete is 10-20% water and he was concerned about that water getting trapped in and mold issues (but he doesn't work with ICF, so not sure he knows).

To the other pp, it's a zone 4 tornado area and we plan on owning this home for a generation+. We will see plenty of warnings/watches.

[Anonymous]

In general, ICF has been around for angood while now. It is pretty commonly used up north, to get better R-value of insulation.

Does your architect not have experience with this ? I would expect an architect in Tornado Alley to know all about using ICF and a poured foundation to create a safe basement.

[Anonymous]

"A pro/con one builder gave was that concrete is 10-20% water and he was concerned about that water getting trapped in and mold issues (but he doesn't work with ICF, so not sure he knows)."

This is nonsense and a sign this is a guy to avoid.

[Anonymous]

Anonymous wrote:ICFs are a good system but hard to find contractors who use it. Most contractors are tied to using traditional forms that are removed at the end of the pour. ICFs are a pain in the neck to set up and you have to be super careful during the pour. However they stay in place and add a lot of R-value to the structure. You do need to follow specs carefully however and ensure they're covered in something on the exterior before backfill.

You don't want to be adding R-value to interior walls. In modern construction, the perimeter of the basement is insulated and the interior is conditioned. This makes the space above more comfortable. An insulated room in the basement is going to make the room above cold.

[Anonymous]

I would think a safe room is something that needs to be designed so that it's actually safe. Like, does it need a reinforced roof so that if the house blows over you don't get crushed? Maybe random answers on the internet aren't quite what you need.

[Anonymous]

Thanks all this was helpful. We are at the front end of the search and will make sure the architect has experience designing for ICF.

For last pp, safe rooms are definitely designed with a reinforced roof as well, along with the door which can be a weak point.

There's actually good info online and on the FEMA website, I was just curious to hear from someone who has experience with it.

[Anonymous]

Sorry, stupid question: with weather events predicted to become more extreme, are you absolutely sure you want to build there for a generation+?

[Anonymous]

Anonymous wrote:

Anonymous wrote:ICFs are a good system but hard to find contractors who use it. Most contractors are tied to using traditional forms that are removed at the end of the pour. ICFs are a pain in the neck to set up and you have to be super careful during the pour. However they stay in place and add a lot of R-value to the structure. You do need to follow specs carefully however and ensure they're covered in something on the exterior before backfill.

You don't want to be adding R-value to interior walls. In modern construction, the perimeter of the basement is insulated and the interior is conditioned. This makes the space above more comfortable. An insulated room in the basement is going to make the room above cold.

Insulation at perimeter basement walls is a code requirement whether it is achieved by batt insulation or ICF.

[Anonymous]

Anonymous wrote:
Sorry, stupid question: with weather events predicted to become more extreme, are you absolutely sure you want to build there for a generation+?

So folks should empty out of the Plains States and Midwest (well, in greater #s than the youth are now)?