What are the pro's and con's of using Durisol ICf for a foundation? Any info on installation speed of these blocks is also appreciated: ie SF/hour/man Thanks

Before all the EPS folks start bashing, here is an analysis based on my experience. I have used both and can offer the following points:

Actual Cons:

1. The blocks are heavier. They weigh the same as a typical CMU while covering 3 times the wall area. It is certainly mangeable and wouldn't be a "deal breaker", but it is worth considering. Of course anyone who is only used to carring the EPS forms will find it very heavy and will complain. Those coming from a more traditional construction background don't seem to complain as much.

Perceived Cons that aren't true:

1. Weaker structurally. While it is true that Durisol system provides a screen - grid of concrete instead of a more "monolithic" pour, The Durisol system is more than structurally adequate and all designs regardless of the system are required to meet the local building codes. This means that whether you use a flat wall ICF, Screen-grid system, or post and beam system they will meet the structural requirements of your local code. It typically comes down to reinforcing and for foundations/basements, the strength of the wall in bending will be the same. The Durisol might use a little more rebar, but in terms of actual cost difference for this rebar, it is minor. We have done 14ft basement walls with no problem.

2. Waterproofing. Durisol is a porous free-draining material. This means that it won't wick, absorb or suck moisture like concrete block or fine cracks in a monolithic concrete wall. I have heard arguments that it is to porous for basements, but in fact the opposite is true. There is no capillary suction in the outer layer of the Durisol wall that will draw the moisture through. There are a number of one-step waterproofing systems that you can use over the durisol. Proper detailing at the wall/footing is important (as it is with any system). I personally like the added protection of an air-gap membrane as well - it is typical for any foundation/basement in my area regardless of the method of wall construction.

Pros:

1. It is a pre finished wall that you can leave exposed on the interior of your basement if you wish. This meets all fire codes. It does not burn or melt.

2. You can attach/screw to any point on the Durisoil surface.

3. It acts as humidity regulator. Without getting into the scientific details (visit their site for more info), it is probably the only approved (in Ontario) wall aseembly that does not require a vapour barrier.

4. Can use 8" slump and less worry about voids. Voids typically occur when air gets trapped in the form. With durisol, the material being porous will allow air out through the sides as the concrete flows down.


There are other performance pros, but they aren't as applicable for below grade/ basements.

I forgot to talk about installation time. Typical is about 60 - 90 blocks per person per day averaged over the project from start to pour. we just did a foundation wall with 2 guys. 900 blocks in 7 days. They were completely new at it and for first time, they averaged about 65 blocks per man per day. It only gets faster after the first one.

70 to 90 blocks per day per man sounds a lot. This is 17.5 SF/hour to 22.5 SF/hour if we using the 24" long Durisol blocks. For ICF we are running around 10 to 12 SF/hour over a full basement project with some windows/doors. What are the "secrets" to this high SF/hour?

If my crew isn't installing 70 blocks per day per man at least, they won't be working long. (I have good guys) 70 on a residential house below grade is fine to use. When we are doing industrial, you should be looking more at 110 plus, at least. We took a 1/2 day training course over 12 years ago at the Durisol facility. That helped back then. Most guys with concrete experience/ICF experience should be fine at that number. Short learning curve at the beginning, but I can't remember back that far!

Not to split hairs, but we don't run a 9 to 5 operation. We typically work 10 hours a day. These means around 12 - 18 sf per manhour. With 10 hour days, it means that 1 hour for breaks and lunch is only 10% or the day as opposed to the 12.5% of the day if it is 8 hours per day. Also, this principal applies to morning prep and evening shut down. All these non-productive activities are a smaller percentage of the day which results in about 7 - 10% increase productivity. This would put your productivity at around 11 to 13 sf per manhour. Even working 4 days a week (which we don't), 10 hour days would make more sense. If you have more crews than jobs, then you can even switch crews after 40 hours and run 2 crews per week and stay within 40 hours. None of this works as well when it's winter and daylight is short.

Best productivity for us with Durisol is 3 guys - with one on the wall and 2 guys feeding, supplying, prepping. It is also important to have the blocks positioned correctly around the wall and having a good foreman makes all the difference in making sure that everyone is working and no one is standing around staring at their feet. Even having one guy take lunch while the other makes a wood buck keeps things moving along. Then switching so the other guy can take lunch results in a buck being made by 1pm instead of 1:30 (depending on the size of the buck, etc). Do that for 7 days and you have an extra 3.5 hours of work done at no extra cost.

The only "secret" is having a good foreman and making sure we are maximizing productivity and actual working time. I don't actually think that you are that far off at your current 10 - 12 sf per manhour. I can certainly see you getting up to 12 to 14 anyway! 18 sf/manhour for us means lots of long walls.