anyone have any ideas what would be the best way to remove some foam from an icf wall for inspection. I need to remove about 10 sections of foam between ties (logix block) on a 20foot wall from top to bottom i know a sawz all and hammer will work but im wondering if anyone has a way to do it any quicker or cleaner thanks

A large angle grinder with 7"+ diameter abrasive wheel will allow you to cut through 2-1/2" foam down to the concrete. Another option would be a an engine driven concrete saw with 14" abrasive blade. Those are pretty expensive tools, but you might be able to rent one for a day for a reasonable price. You would more than likely need to cut vertical slices in the foam between ties because removal of the ties would be difficult since they are embedded in the concrete.

Get an 8" circular saw. Put the blade on backwards. Set the blade to to the depth of the foam. make two parallel cuts top to bottom. Use a flat bar to rip off the foam. After inspection, get some 2-1/2" foam from Home Depot to replace that which you ripped out. Clean up the mess and have a beer.

Use a throw away electric chain saw and scarf out what you need. How big do the inspection holes need to be and if I may ask, WHY??

fbbp, i have to remove from top to bottom between ties in about 10 locations. The reason is consolidation problems in the bottom area. and it needs to be inspected to make sure its localized to just the bottom

If you do not mind me asking, did the ICF installer use a vibrator?  What concrete mix was used?

Be sure to let us know what you find.  We all could use some feedback since very few ICF walls ever have the concrete exposed.

Simple answer to the basic question: Diesel fuel. Clean-up is a bit messy, and don't smoke around it.

Mechanically, it ain't easy. Use a sharp hoe to get off what you can, then large wire wheel.

Do the Logic ICF blocks have slots or grooves on the inside of the foam? If so, that will make mechanical removal more difficult. If smooth on the inside, it shouldn't be that difficult to pull down the foam once you have some vertical slots cut in it.

A few more questions. How did you determine that you had consolidation issues? Did your window bucks have a slot in the bottom to allow filling the forms below the windows ? How thick is the concrete core in these ICF walls? How much horizontal rebar was installed? Is the horizontal rebar splice laps side-by-side or one on top of the other?

Posted By tjetson on 01 Apr 2011 03:55 AM
fbbp, i have to remove from top to bottom between ties in about 10 locations. The reason is consolidation problems in the bottom area. and it needs to be inspected to make sure its localized to just the bottom

Understand that it is to check consolidation issues but who for? Home owner, yourself or an engineer? Honey comb or lack of consolidation is somewhat predictable in ICF structures. While not a good thing it tends to happen more often at the bottom at the beginning of a pour. The aggregates separate as they free fall to the bottom. This usually would only occur at the beginning of a pour as after that the concrete slides along a slope and stays in mix. The other place where honey comb is often found is where there is extra rebar placement such as over windows and doors. Without vibrations and proper mixture some of the early falling stone can land on this bar and block the balance of the concrete from properly embedding the bar. Structurally this is a much bigger deal than small patches at the bottom. Normally there would be very little chance of honey comb at the top 1/3 of the wall. The other big reason for honey comb is over sized aggregate. This will show up more often in ICF with less openings in the web as there is little sideways flow between cells. Based on the above I would not waste time stripping many areas. I would look to the areas next to windows and doors etc. If there is no cladding on either side of the wall, the first thing I would do is place a very bright light (500 watt halogen work light) in the inside of the house after dark and than walk around outside. This will show almost all areas of extreme (structurally significant) honey comb. Also tapping the walls at suspect places with the flat of your hand will sound quite different if the is not good consolidation. In these areas you might also want to probe with a thin blade screw driver or some other tool. If non of these procedures show any concern I would not go to the extreme of uncovering the concrete. If you still need to open the wall to physically see the concrete, in conjunction with an electric chain saw you might try to acquire or make a blade for a reciprocating saw similair to what the auto glass people use to remove windshields.

What is the fix - inject expanding concrete into the hollow area?

Find someone with an infra-red camera and they might be able to find voids in the concrete.

here is a link to the thread with the images

http://www.greenbuildingtalk.com/Fo...fault.aspx