Concrete House questions

[TiTRD]

I wonder if we have talked about that house before the top picture looks familiar and very much like something i want to shoot for

thanks for sharing the pictures. looks like I was off on my thoughts about ICF, that helps a bunch

No idea, I'm just pulling pictures off Zillow.

He doesn't live here anymore, so here's the full deal:

246 Weatherbee Hill Rd, Weathersfield, VT 05156 | Zillow

246 Weatherbee Hill Rd, Weathersfield VT, is a Single Family home that contains 2200 sq ft and was built in 2015.It contains 3 bedrooms and 1 bathroom.This home last sold for $285,000 in September 2020. The Zestimate for this Single Family is $363,900, which has increased by $7,203 in the last...

www.zillow.com

 

[arse_sidewards]

there isn't a concern with using non-treated wood sitting on the shelf?

Any sort of moisture barrier will be sufficient.

 

[XtremeJ]

I designed and built our home in 1995 using foam forms and concrete. Not the ICF 4 x 8 panels, these were 2" thick x 6" tall x 8' long and you used plastic spacer ties to set them apart to your wall width, The spacers also had notches to hold rebar in place both horizontal and vertical.

I poured 8" lower walls and 6" upstairs, total wall thickness is stucco plus 2" foam plus 8" concrete plus 2" foam plus drywall. So you need to account for these "thick" walls in your design. But as the house was designed to have huge solar gain and be energy efficient I wanted the thermal mass and the high R value

Used a hand saw to cut the foam, and it was really easy to put together. You then braced the assembled walls by screwing 2 x's into the outer side of the plastic ties, and I braced the upper edge of the wall with a 2 x either side and tied to together with another 2 x across the top of the wall if needed.

Was super easy to assemble, and then have the pump truck show up, and your wall was basically done. Stucco exterior and drywall interior (drywall screws to the plastic spacer ties), though you could do plaster interior. The only trade that really hated it was the electrical guys because you have to channel the foam for any wiring runs. I took a piece of thin metal and bent it into the shape of the channel and then used a soldering iron to heat the shape and it cut through the foam like butter (like using heated wire to cut our foam wing shapes for gliders).

The gable ends of the building to the roof were framed using 2x's and I just laid a pressure treated piece of lumber on the upper course of concrete, much like you would do on a foundation wall. Just put the bolts in and tied them off to the plastic spacer ties then poured the wall. For the floor, the upper level is on the ledge created by the narrower upper level wall. The lower floor I used pressure treated lumber as a ledger board (I think that is what it is called). You can run the bolts for this like anchor bolts and they can be in place before you pour the wall. or run threaded rod through the entire wall, or even drill anchor bolts in post pour (not recommended)

IF I did it again,
- I would budget to pour concrete every 2 foot of wall lift - I only did 2 x pours, lower level was between 10 and 16', upper level was 8'. Doing a tall wall required an extreme amount of bracing (reused the 2x's for interior walls) and with the wind in the Colorado foothills it meant having to ensure walls were straight as the trucks were arriving on site after an overnight storm. If you did small lifts you can pour in the morning and have the next set of forms done in the same day. Heck depending on location you could pour concrete again in the afternoon. Cost vs time savings is close to a wash,

I would not form out the windows, certainly any on the smaller side. Time and materials framing them out, and bracing them - would have been quicker and easier to concrete saw them out later. Even better if you plan your rebar accordingly.

If you insulate your foundations you don't have to pour below frost depth depending on your area of the country.

When I budgeted out the building I was prepared to pay more for items IF I thought they paid back within 10 years. Better glass, concrete vs wood etc. We use between 1/4 and 1/3 of the propane that our neighbors in stick built homes use. I would roughly guess the extra cost was justified in around year 8 or 9.

I am about to do concrete work for a shop at the house, I intend using Monoslab for the insulated forms. More expensive, but once you pour you are done, and the savings on heat start with the first cold snap. Also I don't have to dig as deep for site prep, a major consideration given the nature of the terrain I am dealing with

 

[Provience]

I designed and built our home in 1995 using foam forms and concrete. Not the ICF 4 x 8 panels, these were 2" thick x 6" tall x 8' long and you used plastic spacer ties to set them apart to your wall width, The spacers also had notches to hold rebar in place both horizontal and vertical.

I poured 8" lower walls and 6" upstairs, total wall thickness is stucco plus 2" foam plus 8" concrete plus 2" foam plus drywall. So you need to account for these "thick" walls in your design. But as the house was designed to have huge solar gain and be energy efficient I wanted the thermal mass and the high R value

Used a hand saw to cut the foam, and it was really easy to put together. You then braced the assembled walls by screwing 2 x's into the outer side of the plastic ties, and I braced the upper edge of the wall with a 2 x either side and tied to together with another 2 x across the top of the wall if needed.

Was super easy to assemble, and then have the pump truck show up, and your wall was basically done. Stucco exterior and drywall interior (drywall screws to the plastic spacer ties), though you could do plaster interior. The only trade that really hated it was the electrical guys because you have to channel the foam for any wiring runs. I took a piece of thin metal and bent it into the shape of the channel and then used a soldering iron to heat the shape and it cut through the foam like butter (like using heated wire to cut our foam wing shapes for gliders).

The gable ends of the building to the roof were framed using 2x's and I just laid a pressure treated piece of lumber on the upper course of concrete, much like you would do on a foundation wall. Just put the bolts in and tied them off to the plastic spacer ties then poured the wall. For the floor, the upper level is on the ledge created by the narrower upper level wall. The lower floor I used pressure treated lumber as a ledger board (I think that is what it is called). You can run the bolts for this like anchor bolts and they can be in place before you pour the wall. or run threaded rod through the entire wall, or even drill anchor bolts in post pour (not recommended)

IF I did it again,
- I would budget to pour concrete every 2 foot of wall lift - I only did 2 x pours, lower level was between 10 and 16', upper level was 8'. Doing a tall wall required an extreme amount of bracing (reused the 2x's for interior walls) and with the wind in the Colorado foothills it meant having to ensure walls were straight as the trucks were arriving on site after an overnight storm. If you did small lifts you can pour in the morning and have the next set of forms done in the same day. Heck depending on location you could pour concrete again in the afternoon. Cost vs time savings is close to a wash,

I would not form out the windows, certainly any on the smaller side. Time and materials framing them out, and bracing them - would have been quicker and easier to concrete saw them out later. Even better if you plan your rebar accordingly.

If you insulate your foundations you don't have to pour below frost depth depending on your area of the country.

When I budgeted out the building I was prepared to pay more for items IF I thought they paid back within 10 years. Better glass, concrete vs wood etc. We use between 1/4 and 1/3 of the propane that our neighbors in stick built homes use. I would roughly guess the extra cost was justified in around year 8 or 9.

I am about to do concrete work for a shop at the house, I intend using Monoslab for the insulated forms. More expensive, but once you pour you are done, and the savings on heat start with the first cold snap. Also I don't have to dig as deep for site prep, a major consideration given the nature of the terrain I am dealing with

hadn't in the least considered doing 2 or 4' lifts.

really seems like forming the windows in would be simple I was thinking to just screw some wood squares into the frames with some plastic around them, pour, then break them out after and chip it near smooth to set windows in

maybe more simple if done in lifts? certainly a spot where a precast has an advantage

thanks for the thoughts and good to hear that it has worked out for you pretty well. 9 year payback is pretty dang good, i'm shooting for 20+ years in one spot so i'd like it to be done halfway well

 

[Provience]

Yeah you'd want to do all that too just for your house! But with this method you place your slab, then keep placing walls on top of it.... Crane ces in and sets them in place on the slab. It's like a flat pack concrete house!

well fuck, that makes sense

 

[[486]]

I bought just enough plywood to form up enough wall for the minimum order of concrete, with my 10" below grade, 6" above grade ideas it ended up being 10 sheets that I needed
figure it'll have a lot of cold joints (or whatever you'd call them) but with rebar in there it'd still be 1000X better than block walls

also, you want EPS not XPS, the XPS is open cell with all the plastic extruded continuous where the EPS is closed cell due to it being a bunch of expanded beads welded together

 

[Provience]

I bought just enough plywood to form up enough wall for the minimum order of concrete, with my 10" below grade, 6" above grade ideas it ended up being 10 sheets that I needed
figure it'll have a lot of cold joints (or whatever you'd call them) but with rebar in there it'd still be 1000X better than block walls

also, you want EPS not XPS, the XPS is open cell with all the plastic extruded continuous where the EPS is closed cell due to it being a bunch of expanded beads welded together

that's a good thought on doing basically 1 load sections.

guess i'll have to actually price out what the rental places charge for wall forming stuff, seems easier enough to just break it up into shorter days.

as for the cold joints, not really a big deal especially if you know they are going to be there, it is very easy to "form" a lip or dip into one side, place some elmers (white concrete glue, whatever brand) glue on the cold joint, make sure the rebar is sticking out or plan on using ~18" rebar half and half to tie them together and they'll pretty well be set

 

[Provience]

Comparing EPS Insulation and XPS Insulation - Today's Homeowner

Compare EPS and XPS insulation to make an informed decision. Learn the benefits of each and choose the best option for your project.

innovativebuildingmaterials.com

Two options, however, tend to stand out as the most popular picks for builders: EPS, short for expanded polystyrene, and XPS, short for extruded polystyrene. These two forms of insulation have many things in common: they are both made of polystyrene resin, they both use trapped air as their insulating medium, both have a closed-cell structure, and both fall under the same manufacturing standard of the ASTM C578, Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation.

EPS insulation is the preferred insulation option by builders for insulated concrete forms, structural insulated panels, and exterior insulation and finishing systems. It has the lowest R-value rating at just R-4 per inch. However, its actual R-value of foam insulations varies, depending on the density of each sheet of insulation. The higher the density of the product, then the higher the R-value will be.

When you compare EPS and XPS insulation at the same R-values, EPS insulation can be between 10 to 30 percent less expensive and costs about 19 cents per sq. ft. for a single, 1-inch 4×8 sheet.

well, huh, I was thinking the XPS was supposed to be the cheaper of the two, apparently EPS is cheaper.

they are both about close enough in everything that the only difference between them will be cost, and they are both cheaper than fancy cut or spray'd closed cell foam

 

[Provience]

Comparing EPS and XPS Insulation

EPS and XPS solid insulation have been used in construction. This author cites evidence to compare the two.

www.concreteconstruction.net

this image from a 15 year below grade real world use "test" makes the best case for EPS. I'd say the retained R value is worthwhile even if the cost were not compelling.

 

[RusM]

that's a good thought on doing basically 1 load sections.

guess i'll have to actually price out what the rental places charge for wall forming stuff, seems easier enough to just break it up into shorter days.

as for the cold joints, not really a big deal especially if you know they are going to be there, it is very easy to "form" a lip or dip into one side, place some elmers (white concrete glue, whatever brand) glue on the cold joint, make sure the rebar is sticking out or plan on using ~18" rebar half and half to tie them together and they'll pretty well be set

When it's planned it's a construction joint! You'd want a keyway in between the new and old concrete, basically just throw a 2x4 in the middle of the forms for the wall so it makes in indent into the wall the new concrete can flow into when you place it.

 

[Ebs]

I see a lot of dudes working in sandals so I'm not sure if this is shoddy third world shit, but the structural insulated panel builds look pretty fast and straight forward.

 

[aczlan]

They are a LOT of work, here is someone building one: My Industrial Cabin Build

Aaron Z

 

[Tiha]

May not have any pricing for you but I am in a earth type home. South side is not covered. Stick and asphalt roof.

Walls are poured concrete 8" 10ft tall. Bedrooms all have windows. South side is brick faced making it over 12" thick with large windows.

1 floor no basement.

I have to say it is the most solid, sealed up, quiet and efficient home I have ever been in, but I often have to run the AC even in december living in the upper midwest. Been wanting to add an attic fan.

the attic has 20' of blown in insulation.

The weather alert will go off on my phone and I will have no idea there is a storm out there until I look. Maybe thunder and lighting at night. rain and hail we never hear.

Roof requires maintenance but that is it. Pretty easy to care for. Wife wants windows not because they leak, but because they open the "other" way LOL.

Wish my garage and barn were concrete.

 

[arse_sidewards]

How does one go about forms for a garage door opening in a concrete wall?

 

[Thefishguy77]

I priced ICF mix for our house project and got quoted $155/yard delivered. Best advice I can offer assuming this if for your property is call the closest concrete plants and see what they charge delivered to your place. There are Several ICF contractors In the Spokane area and eastern Wa in general that can give you a price on blocks. Or you could just buy the blocks and hire 2BB to come out and mix 2-300 yards for you. Bet he gets it done before noon if you are mixing it yourself then it will be cheaper but you will need to plan cold joints and such, not hard just planning.
My neighbor built one when wood was still cheap. He said it will not pay for the insulation savings in his lifetime and he was an HVAC contractor before moving out here. That said his furnace very rarely runs and his heat pump is the same. But its damn near small arms proof so there is that

 

[Provience]

How does one go about forms for a garage door opening in a concrete wall?

same way you form up anything else.

personally i'm a fan of rental concrete forms because they are modular and easy and designed around tie systems. garage door would be all the same as anything else, form up your typical wall on the sides, close off the ends, pick how ever high you want the door to be, and form across that gap and use support bracing under the "trough". obvious use rebar in the shape to help the concrete across the span.

biggest downside to the ICF is the foam on the exterior side, guess it depends on the cost of paying for the foam and then doing a siding on top of that versus rental for the forms and then not needing to do a siding.

rental forms around idaho seem to be ~$1.50 / square foot (includes both sides) of wall and including braces and ties if i'm remembering right. maybe it was $1.75 with bracing and ties, and per week of time.

 

[Provience]

May not have any pricing for you but I am in a earth type home. South side is not covered. Stick and asphalt roof.

Walls are poured concrete 8" 10ft tall. Bedrooms all have windows. South side is brick faced making it over 12" thick with large windows.

1 floor no basement.

I have to say it is the most solid, sealed up, quiet and efficient home I have ever been in, but I often have to run the AC even in december living in the upper midwest. Been wanting to add an attic fan.

the attic has 20' of blown in insulation.

The weather alert will go off on my phone and I will have no idea there is a storm out there until I look. Maybe thunder and lighting at night. rain and hail we never hear.

Roof requires maintenance but that is it. Pretty easy to care for. Wife wants windows not because they leak, but because they open the "other" way LOL.

Wish my garage and barn were concrete.

i'm trying to avoid an A/C system completely. are you running it just for moisture control? do you have anything on the interior side of the walls or just the 8" of concrete?

 

[rfr002]

ICF is going to be 8" thick, every sq foot is going to be .66 sq ft of concrete or 40 sq feet per yard. icf block are $7-$8 a sq foot on top of the concrete. ICF is also going to have to be pumped, so I would figure $180-$200 a yard pumped. So balpark $12 a square foot of wall.

2x6x8 is $13
7/16 osb $50

40' long wall =47 2x6 + 10 osb = $1100, or $3.43 a square foot + insulation so lets say 4.50 a foot for a wall.


cliffs, icf is about 3x more expensive even in todays retarded lumber market.

You forgot to add insulation to the cost of stick built. It will still be cheaper but it closes the gap some.

We have been looking at building a house and are considering ICF. One thing not mentioned (or at least not directly), is how well sealed the house is. From what I am hearing, blower door scores well below 1 are basically the standard and achieved without any real extra work. This could be a huge factor if your area has air quality issues (either pollution or allergens).

Another thing to think about is AC systems. Make sure whoever is designing it is familiar with ICF. You can typically downsize the unit a noticeable amount. If you live in a humid area (like us in south Louisiana) do plan on a dehumidifier since the AC won't run enough to knock the humidity out.

 

[PAE]

Monolithic concrete poured underground dome house is what I would build given time abd funds.

 

[Tiha]

i'm trying to avoid an A/C system completely. are you running it just for moisture control? do you have anything on the interior side of the walls or just the 8" of concrete?

The interior is completely finished. Furring strips, insulation in between and plastic over the top before the drywall. So another 1.5" thick roughly.

With large southern facing windows we need the AC. If it is a bright sunny day, even at 40 degrees with the curtains closed my house will hit 80.
I think an attic fan would save some money over AC but having windows open also allows dust and dirt in.
Opening windows when it is 30 degrees out is almost shocking, the incoming air is not comfortable. Hard to enjoy it.
They make hybrid systems that will pull outside air if it is cooler than the house, filters it and circulates it. Still running the blower fan though, but I suppose not running the ac compressor saves money.
We are going to try one when ours gives up.
We looked at heat pumps, geo thermal, nothing really fits our situation that well.
Rooms with tile, hardwood or vinyl flooring are cooler than carpeted rooms. Not sure how much but certainly noticeable.

Humidity and moisture have never really been an issue. Before they buried the house it was tared and insulated on the outside.
Had window well in one bed room collapse, then when it rained the water came in around the window. Drywall got wet. had to cut it out and replace. Otherwise no problems.

In all it is still cheap. have basically 5 adults living there. 2 kids going to college from home. Wife working from home. Other daughter and grandchild staying with us for a bit. All the showers, cooking, tvs, internet, computers, blow driers, curling irons, a washer and drier that never stop. Daughter has a dorm fridge. It is really heard to tell what is heating and cooling vs other in the utility bills, but our highest bill has only ever been $237.

 

[[486]]

How does one go about forms for a garage door opening in a concrete wall?

I'd do it same as you would with brick, heavy angle iron lintels
Actually, I'm planning on angle iron window frames, so that I can do some massive fucking shutters and weld hinges anywhere on them

Leaving for the weekend? Close the hatches and bar them from the inside.

 

[[486]]

if you are mixing it yourself then it will be cheaper but ...

no it will not

unless you're getting
3/4 washed gravel cheaper than 350 a 12yd load
sand cheaper than 100 a 12yd load
and portland cement cheaper than $12 a 94?lb bag

I found a deal on cement for $3.50 or thereabouts a bag, so I bought three pallets worth. I'll be mixing some but nowhere near all of it in mine.
With the above figures it is cheaper to get a load of 3k psi delivered, but doing it that way you gotta find a place to put 4+yd before it sets up

 

[rockmup]

I got a quote for 54 yrds of 4000psi concrete in October of 2019 @ 110.00 delivered, I fucked around and the quote last week was 195.00 a yard

 

[rockdog57]

You’re still going to need wood on the inside to get somewhere to put insulation. Icf is pretty do it yourself where walls poured in forms are gonna cost ya to have someone do them. Unless you have access to concrete forms somehow.

 

[[486]]

You’re still going to need wood on the inside to get somewhere to put insulation. Icf is pretty do it yourself where walls poured in forms are gonna cost ya to have someone do them. Unless you have access to concrete forms somehow.

my idea is to slap the insulation on the outside, so the thermal mass in on the inside and the walls are nice and durable
they'll probably get plastered with lime to get them smoother

 

[Provience]

You’re still going to need wood on the inside to get somewhere to put insulation. Icf is pretty do it yourself where walls poured in forms are gonna cost ya to have someone do them. Unless you have access to concrete forms somehow.

concrete forms rent for 1.5-1.75 per square foot, not abusive. insulation is rigid foam on the inside, which is why i like poured walls over ICF because i just don't understand the exterior foam, but maybe that is because i'm dealing with a long term cold sitation and heat soak/retention isn't valuable.

but doing 2x4 walls 24" o.c. and having no wind and high insulation is much less lumber than doing 2x6 16" o.c. or needing to go to a dual 2x4 wall to get R~22 or so equivalent knowing the house wrap won't be as wind resistant, plus having to do siding and paint maint.

 

[Provience]

The interior is completely finished. Furring strips, insulation in between and plastic over the top before the drywall. So another 1.5" thick roughly.

With large southern facing windows we need the AC. If it is a bright sunny day, even at 40 degrees with the curtains closed my house will hit 80.
I think an attic fan would save some money over AC but having windows open also allows dust and dirt in.
Opening windows when it is 30 degrees out is almost shocking, the incoming air is not comfortable. Hard to enjoy it.
They make hybrid systems that will pull outside air if it is cooler than the house, filters it and circulates it. Still running the blower fan though, but I suppose not running the ac compressor saves money.
We are going to try one when ours gives up.
We looked at heat pumps, geo thermal, nothing really fits our situation that well.
Rooms with tile, hardwood or vinyl flooring are cooler than carpeted rooms. Not sure how much but certainly noticeable.

Humidity and moisture have never really been an issue. Before they buried the house it was tared and insulated on the outside.
Had window well in one bed room collapse, then when it rained the water came in around the window. Drywall got wet. had to cut it out and replace. Otherwise no problems.

In all it is still cheap. have basically 5 adults living there. 2 kids going to college from home. Wife working from home. Other daughter and grandchild staying with us for a bit. All the showers, cooking, tvs, internet, computers, blow driers, curling irons, a washer and drier that never stop. Daughter has a dorm fridge. It is really heard to tell what is heating and cooling vs other in the utility bills, but our highest bill has only ever been $237.

Thank you for the clarification. I'm surprised it gets that hot, but hell, $237 is a pretty low "max"

 

[Provience]

my idea is to slap the insulation on the outside, so the thermal mass in on the inside and the walls are nice and durable
they'll probably get plastered with lime to get them smoother

you're also in the frozen north, while i'm not trying to change your mind, be mindful of using exterior wall for thermal mass, as opposed to like a central large fireplace surround.

thermal mass is a battery/strorage for heat. If you insulate the outside, then you will constantly be adding heat to the storage system, if you insulate the inside, then you are only adding heat to the living space.

in the frozen north, with long periods of low temperature and not large temp swings, the battery effect is less useful because your walls wont be releasing heat back into the house, you will constantly need to run the heat. same as insulating the inside, but now you are keeping the battery topped off in addition to heating the living space. It's a rather diminishing return that is only marginally useful for a couple weeks in spring/fall when you get enough temp swing to justify not adding heat and using the battery heat to warm the household

 

[aczlan]

knowing the house wrap won't be as wind resistant, plus having to do siding and paint maint.

Zip siding with their zip tape between sheets and taping the windows/doors in is supposed to be extremely air tight, on par with spray foam.

Aaron Z

 

[[486]]

you're also in the frozen north, while i'm not trying to change your mind, be mindful of using exterior wall for thermal mass, as opposed to like a central large fireplace surround.

thermal mass is a battery/strorage for heat. If you insulate the outside, then you will constantly be adding heat to the storage system, if you insulate the inside, then you are only adding heat to the living space.

in the frozen north, with long periods of low temperature and not large temp swings, the battery effect is less useful because your walls wont be releasing heat back into the house, you will constantly need to run the heat. same as insulating the inside, but now you are keeping the battery topped off in addition to heating the living space. It's a rather diminishing return that is only marginally useful for a couple weeks in spring/fall when you get enough temp swing to justify not adding heat and using the battery heat to warm the household

but on the up-side you don't gotta deal with mold inside the walls
because everything is concrete and cane be hosed down with bleach if anything does start to grow on it