How-to do a T-intersection with Advantage ICFs
Written by: Colin Showalter
Follow Colin on twitter: @Colin_Plastifab
Quite often, I get asked “why doesn’t Advantage ICF have a prefabricated or moulded T-block? And what do I do at a T-intersection when using Advantage”
The answer is simple: Advantage ICF doesn’t have a T-block because fabricating a T-intersection on site is easier, faster and wastes less block resulting in lower costs compared to using a moulded T-block.
Using a moulded T-block may result in more on site cutting of connecting blocks because you will have to cut filler blocks on all three sides of the T-intersection, thus creating more waste. Using a T-block doesn’t allow you to reduce your bracing requirements. Some moulded T-Blocks cost close to twice as much as the standard blocks based on cost per square foot.
So how do you do a T-intersection with Advantage ICF? Follow the steps below and you will reduce your construction cost including the waste and labour at T-intersections.
Preparation: Build strong back “L’s” out of dimensional lumber as required. And pre-bend two 90 degree pieces of rebar per row of blocks.
Working from corners to the middle of wall, build the through wall as you would normally,.
Cut the foam out of the through wall you just built in order to fit in the perpendicular wall. Your cut opening will be 11 ¼” wide for a 6” block and 13 ¼” wide for 8” block. Cut the Advantage web in the wall section you have cut at the third rebar clip from the side where you have cut the foam, leaving the middle vertical strut in the web. Now remove the foam cut out. This will allow you to slide the perpendicular block into the through wall. Use two zip straps approximately 20 inches long and run them through the perpendicular block web around the middle strut of the cut web. Note: Do not over tighten straps.
Place pre-bent 90 degree rebar going all three directions in the “T”.
For further explanation of steps 2 & 3, see the graphic here.
Repeat steps 2 and 3 for all sequential rows of ICF block.
Take your pre-built lumber “L’s” or “strong backs” place these vertically on the inside 90 degree angles of the “T” fastening them to the Advantage ICF ties. Fasten every row.
Fasten a brace the same as the rest of your braces directly on the back side of the T-intersection to support the block to resist the high concrete pressure at the T-intersection.
Following these steps will allow you to build a monolithic concrete wall at any T-intersections in your project. Be sure to follow all local building codes.
You can learn more about Advantage ICF details on the website www.advantageicf.com
Coming soon: Better footing, better results! Guest writer Wade McClelland