Electrical Shed/Bunker - Stick, block, or ICF? Lessons learned or suggestions?

[skyking1]

No, you'd have a structure that would sweat with condensation, be structrurally vastly inferior to a concrete wall.
The insulation on the ICF makes it into a heat mass that moderates the temperature swings.

 

[HarryN]

Moisture is going to flow to some extent through any masonry wall, footing or foundation.

Some common methods to reduce this are:
- Using visqueen or equivalent barriers
- coating the wall with a rubberized coating designed for this
- Gravel between the "dirt" and concrete or concrete blocks
- Designed in corrugated drain pipes to carry the water around the building

What ever you think you need to do, do it 2x and it really does help.

I am mixed on the poured concrete wall vs blocks.

It is not always so easy to get a good pour in difficult to reach areas, which can result in mediocre results.

On the concrete block side, there are blocks that are poured from left overs - really for garden / decoration, and there are really strong blocks out there as well that are surprisingly good.

 

[skyking1]

ICF are insulated in and out. It is not about moisture moving through and you apply waterproofing for that. It is having a bare concrete surface to condense moisture from the air.

 

[kennyb]

I backfilled 4ft of mine to get around the height restrictions on accessory buildings. I used some roll on rubberized waterproofing. 2 coats and it's sealed. Tie your wrb into it and your fully air sealed. Henry sells a product blueseal? I believe.

The benefit of the icf is that it acts as a thermal break. Because of that it allows the concrete to act more like a thermal battery instead of a heat sink. Also since it's reinforced it'll resist soil and hydrostatic forces better than a block build would (imo).

One idea for a 3 side burried build I had, would be to get solid big o and burry it in lifts around the foundation. Have one side enter the building low, the other high. You should be able to put a small ventilator fan on it and the heat from the soil should help maintain a year round air temperature inside.

 

[doing it different]

I backfilled 4ft of mine to get around the height restrictions on accessory buildings. I used some roll on rubberized waterproofing. 2 coats and it's sealed. Tie your wrb into it and your fully air sealed. Henry sells a product blueseal? I believe.

I would delta wrap after sealing. I acts like gravel. And leaves an air gap between the wall.

 

[kennyb]

I would delta wrap after sealing. I acts like gravel. And leaves an air gap between the wall

totally. in this instance we used delta and then 2" limestone as fill. keeps any and all water away and right down to the footing drains and made a great base for the rock "retaining walls".

 

[doing it different]

To much stone backfill means alot of water comes down through the tile fast!! Make sure sump pump etc can handle it... also I am a fan of putting poly sideways around the perimeter, maybe 6-12 inches below grade... makes a good thermal break for frost. But also helps shed water past the overdig. And you have less water hitting the tile.

 

[quantum`]

The benefit of the icf is that it acts as a thermal break. Because of that it allows the concrete to act more like a thermal battery instead of a heat sink. Also since it's reinforced it'll resist soil and hydrostatic forces better than a block build would (imo).

Not just an opinion but proven fact. ICF is a reinforced concrete wall, whereas CMU is just brittle blocks. Here in the PacNW block homes fall apart in seismic events whereas reinforced concrete walls wobble, at worst. The latter is the most seismic- and disaster-resilient, if this is a consideration. A 'box of rock'.

 

[immortl]

Alrighty, ICF it is, along with good external waterproofing and overdo the drainage part of the build as well.

Seems to me this is a great opportunity to synergize some costs. As mentioned earlier, I need to have a structure on the property with a permanent foundation to qualify as 'real estate'. Let's use the ICF electrical bunker as this structure. Main part will be the electrical area. So, how do we add a 2nd floor to it like @kennyb did? And thank you Kenny, it was your post that gave me this idea. An open 2nd floor room qualifies as the 'place to lay my head' for the bank's purposes and I'm more than certain I can find a use for it.

Do I cap the first floor with concrete or traditional wood? How? For the 2nd floor should I do ICF again or do a traditional wood stick build? What else can/should I do?

 

[skyking1]

In the OP's case (and mine) there is no sump pump, the footing drains just daylight away.
There is typically little water movement below grade. Most is surface water that you can manage and divert around your structrures. If you catch and manage surface sheeting flows, the loads on footing drains are minimized.
If you do have some subsurface flows, I like to capture them at a distance from a structure, a few feet at least with a french drain that is below the footing level.
This creates a dry island of soil around the structure.

 

[skyking1]

Alrighty, ICF it is, along with good external waterproofing and overdo the drainage part of the build as well.

Seems to me this is a great opportunity to synergize some costs. As mentioned earlier, I need to have a structure on the property with a permanent foundation to qualify as 'real estate'. Let's use the ICF electrical bunker as this structure. Main part will be the electrical area. So, how do we add a 2nd floor to it like @kennyb did? And thank you Kenny, it was your post that gave me this idea. An open 2nd floor room qualifies as the 'place to lay my head' for the bank's purposes and I'm more than certain I can find a use for it.

Do I cap the first floor with concrete or traditional wood? How? For the 2nd floor should I do ICF again or do a traditional wood stick build? What else can/should I do?

It is up to you. I am happy with traditional stick framing above an ICF basement. Others, like @quantum` , prefer ICF and concrete all the way.
Here is what would drive my bus:
The cost of delivered concrete at your address, VS framing that you can go get yourself if need be.
IF you go the whole second floor thing, you can sink an ICF basement in a minimum of 6 courses for 96" ceiling and then joists over that, and framing.
If you go all concrete, you'll need a pump truck out there multiple times to take the walls up in two lifts and pour a floor, etc. It is all relative.
I went 7 courses at my place so I could have a zero threshold entry, roll right in no steps. I hung my joists on ledgers where needed. It is more complicated than just mudsill joists and rimboard.

 

[skyking1]

My home build with just a few pictures.

https://diysolarforum.com/threads/hello-retiring-and-building-a-new-home-soon.81492/

The solar thread with a more recent picture.

https://diysolarforum.com/threads/lets-get-my-system-built-this-weekend-on-paper.98560/page-2

 

[quantum`]

SEVEN separate lifts? For a one storey shell I plan on three lifts in one pour and sometimes only get two. By the time you get back around, the first lift has started hardening. Concrete forms, by the Portland cement growing crystals which interlock with sand and other aggregate, so the longer the concrete stays damp the more crystals interlock. This is why ICF walls are so strong; they hold in the moisture for a long period. Also a horiz rebar outside in one course, inside on the next, outside, inside, etc.

You have to make sure a quality block, and put OSB backstops in places where the ICF webbing is compromised, like where you're casting in a load center. And BRACE THOSE WALLS, or you'll be sorry.

Do I cap the first floor with concrete or traditional wood? How? For the 2nd floor should I do ICF again or do a traditional wood stick build? What else can/should I do?

I've always been afraid of fire. So for interfloor decks I use the Hambro D-500 system. (They engineer) Put brickledge ICF on the top course so the steel girders have plenty of resting support. Put in cross-bars (Hambro lends) and OSB between the girders. (They don't like OSB so don't tell them) Cut down the inside ICF wall by 4" to allow for the deck (So no thermal bridging), and I always staple down plastic then between the girders, for easy release after the pour and a nice finish on the underside... but not on the steel -- it must interlock with concrete. WWM for reinforcing, interlocked with your ICF vertical rebar, and pour 4". Check your finishers to make sure they have a power trowel for smoothness and to make sure 4" thick! Steel girders and concrete deck (and ICF walls) become one composite unit, very strong.

For stairs I bought from Red China the custom stringers with 25mm glass treads, which light up as you approach. (motion sensor) But maybe you'll want to build them out of wood. (I think ill-advised if fire) Def ICF on the second floor I say, and wood roof trusses if you must. I use InsulDeck for rooves which forms a concrete grid.

 

[skyking1]

SEVEN separate lifts? For a one storey shell I plan on three lifts in one pour and sometimes only get two. By the time you get back around, the first lift has started hardening. Concrete forms by the Portland cement forming crystals which interlock with sand and other aggregate, so the longer the concrete stays damp the more crystals interlock. This is why ICF walls are so strong; they hold in the moisture for a long period. Also a horiz rebar outside in one course, inside on the next, outside, inside, etc.

You have to make sure a quality block, and put OSB backstops in places where the ICF webbing is compromised, like where you're casting in a load center.


I've always been afraid of fire. So for interfloor decks I use the Hambro D-500 system. Put brickledge ICF on the top course so the steel girders have plenty of resting support. Put in cross-bars (Hambro lends) and OSB between the girders. Cut down the inside wall of the ICF by 4" to allow for the deck ( No thermal bridging), and I always staple down plastic then between the girders, for easy release after the pour and a nice finish on the underside. WWM for reinforcing, interlocked with your ICF vertical rebar, and pour. Steel girders and concrete deck become one composite unit, very strong.

For stairs I bought from Red China the custom stringers with 25mm glass treads, which light up as you approach. (motion sensor) But maybe you'll want to build them out of wood. (I think ill-advised if fire) Def ICF on the second floor I say, and wood roof trusses if you must. I use InsulDeck for rooves which forms a concrete grid.

where do you get 7 lifts? I had 7 courses of blocks for my basement, not seven lifts. It was a single pour.

 

[cotter`]

OK, this is one of the things I wanted to suss out in this thread, but didn't ask directly. My purpose of sinking the structure into the hillside/ground is to try to take advantage of temperature moderation.

While ICF seems easier to install/build with, might uninsulated cinder blocks achieve the desired temperature moderation a bit better?

Seems like you have decided ICFs, was going to add that the concrete block offer no insulation and will be very cold in the winter.

maybe imbed some bolts into the concrete during the pour to hang strut from then hang your electronics on the strut?

 

[quantum`]

maybe imbed some bolts into the concrete during the pour to hang strut from then hang your electronics on the strut?

Better get them right though. Maybe mount on a jig. Washers on the inside for extra strength.

 

[skyking1]

you can drill and hang bolts in ICF with precision. One of the many nice features.
My ledgers were spot on, I just tightened the bolts up after it cured.

 

[niktak11]

Simpson makes an ICF ledger attachment connector

 

[skyking1]

Simpson makes an ICF ledger attachment connector

I know and in hindsight, I wish I had sprung for those. My attachment is much stouter but not worth the trouble.
The OP does not need to go that route, he can just mudsill and joist and rimboard. That is the fastest easiest method. I did mine for zero entry on the east end only and transitioned to traditional construction on the west end.

 

[quantum`]

Ledgers not necessary with Hambro. And Hambro prevents racking.

 

[Steve777]

ICFs are great, IMO. My house foundation and several other smaller structures used them.

What I did in my greenhouse was spray the inside foam wall with vegie oil just before the pour. This allowed me to strip the foam off the inside fairly easily, and then put that insulation outside. But my ICFs used a plastic connector, so relatively easy to break them off with a spud. This leaves a bare concrete wall inside and double foam outside. It leaves the concrete's thermal mass inside the insulation too, which generally works better.

Not sure why folks here think you need to put up OSB or other wood for fastening things to; concrete is plenty strong. Give the bare concrete inside wall a good coat of sealing paint and you should be good to go, with a fireproof wall for all your equipment, that will hold anything. Definitely seal/waterproof the outside foam, and put in drainage tiles.

Oh, and figure out where your wires and plumbing will need to come thru the concrete wall, and put in sections of PVC pipe to feed them thru, prior to the pour. Make them a bit bigger than you need. You will be glad you did. Maybe even put in a couple of extras.

 

[quantum`]

Not sure why folks here think you need to put up OSB or other wood for fastening things to; concrete is plenty strong. Give it a good coat of sealing paint and you should be good to go, with a fireproof wall for all your equipment, that will hold anything. Definitely waterproof the outside of the foam, and put in drainage tiles.

Yeah, I am always horrified to see electrical equipment on a wooden wall. What are they thinking?! Then again, I've always been afraid of fire.

But, we all make our own decisions... SOMEday regs will require cementitious, after enough fires.

Oh, and figure out where your wires and plumbing will need to come thru the concrete wall, and put in sections of PVC pipe to feed them thru, prior to the pour. Make them a bit bigger than you need. You will be glad you did. Maybe even put in a couple of extras.

True, although it's not a big thing if the hole is less than 1". For my 6" ERV ducts ya, it is an issue.

 

[skyking1]

Ledgers not necessary with Hambro. And Hambro prevents racking.

No kidding. I was using traditional highly combustible framing.

 

[immortl]

I really appreciate everyone's suggestions and thoughts. Somewhat busy with day job and other obligations and not always able to reply quickly, but I am reading it all and looking things up as they're suggested and will come back with additional questions for clarification if needed as I can. Thank you very much everyone, you all are awesome.