Crestone Domes

After the walls are built, you have to think about how you are going to attach your trusses. We chose a truss clip that is only available from Florida. It gets buried into the concrete, and the trusses just slip into it later. Very simple. But you MUST mark everything accurately, and make sure you put them in absolutely straight!!!
We marked the walls with a marker, on both sides of where the concrete goes in. That way, there was a better chance of getting the truss clips in straight.
Then, we checked every position with an actual truss clip, to make sure there was no webs or rebar in the way.
Finally, we went around and put clear packing tape on top of each marking. Why? Simply because you won’t be able to see the marks if (or should I say WHEN) you mess up the top of the wall with concrete.
Pouring walls is extremely messy. So we covered our markings, and after smoothing the top of the walls with trowels, we simply peeled off the tape and stuck the truss clips in.
Often, you don’t have a lot of time before the concrete goes off, so it is important to work quickly. Make sure the truss clips are in straight!!!
Remember, it is all set in stone.

Tags: truss clips

After filling the stemwall, we put ice and watershield around the outside and had it backfilled. Then, we started building the walls. Make sure you mark where all the windows and doors go, and remember to calculate for putting wooden bucks in.

We made the window bucks out of 2×12 lumber on the sides and tops. On the bottom of the buck, we simply put 2 pieces of 2×4 across with a space in the middle, so you can easily fill concrete under the windows. The opening in the ICF should be the rough opening of your window + 3″ in both directions. That way, your finished opening, inside the buck, will be the exact rough opening for the window.

If you don’t use pressure treated lumber, the buck has to be covered on the outside with either felt paper or ice and water shield so that it isn’t in contact with the concrete. To ensure that the buck stays in place, we put long screws into the sides. These screws will grab the concrete when the walls are filled, and it will be nice and solid. In addition, the bucks also have to be braced with pieces of OSB that are attached to the ICF. This bracing comes off after the pour. You might also consider bracing the inside of the buck in the middle with a temporary 2×4, especially if the window is bigger than a 4×4 opening.

Again, we put rebar on every row and form lock on every other row, as well as horizontal rebar every two feet. Finish the walls off by cutting all the knobs off the top row, foaming all the seams and bracing everything that could pull apart!

Tags: ICF, Nudura

After we got the foundation done, it was time to build our ICF stemwall.
ICF blocks are 8′ long and 18″ high. They can be used inside out or upside down, so they are easy to work with. The only thing to watch out for is that the webs must match. If you look at an ICF block, you’ll see a row of diamond patterns every 8″. These are the nailers that you can use for sheet rock, hanging cabinets from and so on. So, all the webs have to be aligned on top of each other. If you don’t align them, the whole project can become a nightmare.

The other thing to watch out for is that if you need to make cuts, try to cut on a cut-line. Up against the windows, you don’t have to worry about that, but if you have to use smaller pieces of block somewhere, they will snap together without problems if you cut them on the cut lines.

Third thing to watch out for is to alternate the corners every row. The corners have one short and one long side, so on every row, you should have one corner with a long end, and one corner with a short end, and on the next row, you switch them so they are always staggered. This is what holds your structure together.

Fourth thing is to make sure the blocks are snapped together properly. If they aren’t, you can get blow-outs and uneven walls, so knock each block with a hammer to make sure it snapped together properly with the block below it.

To start your first row, just line the blocks up next to eachother. Put your number 4 rebar into the clips inside the blocks and make sure that they overlap 20″. On our stemwall, we put the rebar in the outer clips all the way around.

On the second row we put our formlock in. Formlock is a piece of metal grid made to fit into the blocks and stiffen and straighten the wall. It is a major pain in the butt to put it in, but if you can do it, it does make a difference. Try to plan it so you’ll end up with a form lock row under the windows, and also at the top of the wall. They should go in every 2 rows, while the rebar goes in every row.

Putting in formlock is definitely not a girl’s job. A big heavy guy might be good for the job, or a big heavy hammer. Push, squeeze and knock until you get it in.

The stemwall was supposed to be 3′ high (2 rows). But we built it 3 rows high, and filled it half way up the third block so the join would be inside the block.

Before we could pour the walls, we attached a special ICF bracing system that can hold the walls straight when they are being poured. DON’T try to pour the walls without this system – if it starts to lean when filled with concrete, there is nothing you can do to rectify it. With the support system in place, however, adjusting the walls is easy. You just turn the legs, and the wall will move in or out as needed.

You also need to put in vertical rebar every 2 feet. We drilled the rebar into the slab before we built the ICF wall. Tie it to your horizontal rebar with rebar ties so they don’t move when you pour the concrete.

And last, but not least, all the seams between the blocks were foamed with special ICF foam, and also foamed to the floor. Diagonals were checked, and OSB bracing were put along vertical seams at the top of the wall. Lots of work!

And, if you want to save yourself some grief later, make sure you cover the tops of the walls with feltpaper and duct tape. You don’t want those knobs full of concrete if you are planning to build the rest of your walls in ICF, too. Keep them clean, and you’ll be glad you did…

Tags: Building with ICF

When you buy a piece of land, you never know what you are going to run into. We built a house 3 lots down from this lot, and there was nothing but beach sand everywhere we dug, so naturally, we thought this lot would be the same. We couldn’t have been more wrong. There was just stone upon stone. We ran into two stones about 8×8x12 feet that had to be blown up with dynamite, and the rest of the ground was so hard to dig that the digger broke twice…
Before the digging was over, we were both questioning our sanity – why did we ever even consider building a new house? And the land started looking more and more like a bomb had exploded. Total chaos and destruction! Very depressing. No matter how many houses you build, the destruction of the digging is very disturbing, but this, too shall pass.

Tags: buildign with ICF, building a new house

Whenever you plan out a new house project, it often tends to take on a life of its own. There are always factors that are not in your hands, dreams turn into nightmares, the weather turns nasty, people don’t show up, and nature has little tricks up its sleeve.

To all of you people who signed up for my feeds, I have to tell you that the house is no longer going to be a dome. I still believe that a dome is the very best kind of house you can possibly build, but the question is – how are you going to build it?

In our case, we live in rural Colorado, and there is only one person in the vicinity who has a concrete pump. When he didn’t get back to us with a price, I started getting suspicious. So, before we put our plans in for review with the local POA, I told my husband that we better call and find out if he was still interested in letting us use his pump. (This is not just a normal concrete pump – it is the kind that you tow along behind a truck and hook up to a huge compressor so that you can shoot the concrete onto the walls.)

Anyway, the guy didn’t return any calls, so we went to his house, and there was an angry dog in his yard, and his neighbors told us he was not in the area any more. And without a concrete pump, how do you spray a dome?

If we had enough money, we could have hired a crew from monolithic dome institute, I suppose, but we didn’t have that kind of money. So, we quickly had to redraw a new house, which put us back at least a month.

The new house is a square ICF house, 1600 sq ft, one story. ICF is insulated concrete block, and the brand we are using is Nudura.
We chose Nudura ICF because the Nudura blocks are bigger than the other blocks on the market, and also because the blocks clip into each other very nicely. The corners can be used right side up or upside down, so you don’t have to worry about right and left corners.

We made another ICF house in the past, and they are pretty good when it comes to R-value. (Performance R-value is about R-50). The Nudura block also has places that you can screw into every 8 inches, so this makes it easy to hang kitchen cabinets, sheetrock etc.

It is definitely more expensive than a normal framed house, and a bit more time consuming, too, but it makes a very solid and warm house, and concrete walls don’t burn, and neither do they allow mice in.

The biggest difference between a dome and an ICF house is the fact that the dome has heatmass on the inside in the form of 3″ of concrete, so once you heat it up, it holds the heat incredibly well for a long time, and the heating doesn’t have to come on again for hours and hours. The ICF house doesn’t have heatmass on the inside to hold the heat, but when the heating comes on, it instantly heats the house. Therefore, the heating system in an ICF house has to be adjusted to heat the house in a different way. It has to come on often, and for a very short time, just to top up the heat.

Tags: ICF, Nudura