Nudura ICF Basic Installation Guide

We supply training and site supervision on every project to ensure the forms are installed, braced and poured correctly. As well, we offer training sessions at the Vancouver ICF Training Centre on the last Friday of each month.  To register for training, click here.

We rent Zont bracing for your project, click HERE for information on the bracing.

For a printable copy of the full site installation guide, click here (PDF).

Before You Start...

• Allow 24-48 hours for delivery
• Confirm wall heights
• Provide delivery name & phone #
• Arrange for at least 2 people to unload blocks from 5 ton truck
• Ensure good access to excavation
• Provide 2x4s, electric drill, stakes & #8 wood deck screws
• Rebar, 7" zip ties

Toll free: (604)239-0883 

• Footings should be poured to an accuracy of 1/4". Always use a laser when screeding the top of footings to ensure accuracy.
• Footing steps should be a multiple of 18" to match the height of the Nudura block.
• When pouring the footings, install vertical dowels correctly to ensure they are located between the webs.
• When unloading Nudura, place 2/3rds in the center of the excavation so that the wall can be built and the bracing installed without having to move blocks.
• Snap lines on footings to show the exact location of outside of foam.
• Check the layout for square by checking diagonals.
• Pairs of 16" 2x4s nailed on the outside corners to prevent blocks from shifting during the build.
• Mark out openings for windows & doors on the footing to determine marriage line location.

Typical vertical rebar spacing is 16" O.C. On 8" block, the first vert is set back 10" from the corner (12" if using 10" block); on 6" block, the first vert is set back 6" from the corner. Where verts land close to a joint, offset by 4" to keep clear of the web.

Vertical Joint Hooks (VJH)

Vertical joint hooks (VJH) are supplied in boxes of 200 with the ICF shipment. Place VJH on 8" block connections: for straights, use upper & lower connections on the 1st row and only the upper web on the 2nd row; for corners, use upper & lower connections on the 1st row and the upper web only of every corner to the top of the wall. The claw of a hammer will assist with fitting the bottom VJH. 

• Place corners around the perimeter in the same orientation.
• Build inwards from each corner using standard blocks.
• Use 4 VJHs (vertical joint hooks) on each joint of the first row, 2 VJHs on the second row, and 2 VJHs on each corner joint for the rest of the wall.

• On each wall, a "marriage line" must be created to obtain the exact corner to corner distance.
• The marriage line will run vertically the full height of the wall (this is why it is ideal to locate the marriage line at an opening).
• If the marriage line falls on the web of one of the blocks, cut the adjacent block back two inches.
• Install the horizontal rebar as per engineering drawings. Use zap straps or tie wire to secure rebar overlaps.

Marriage Lines

Use a retractable blade knife to cut the EPS. Create a marriage line to achieve a set dimension; typically one per wall, if possible within an opening area. Fine-tune the cut by measuring 8" out from each side of the joint centre (dimension adjust) so the final overall dimension lands on target. Check overall dimensions (allow 2 5/8" each side additional to concrete dimensions), leaving a 1/2" nominal gap, then use 1x4 strapping to fix each side in place and fill the join completely with foam using the applicator. 

Where a marriage line occurs on a web, move the cut 2 inches away. Where creating a marriage line at a corner, choose the long end of the corner with webs for strapping.

Building a Tee Wall

Where an intersecting wall meets a flanking wall, use ZEE T-Brackets to tie them together:

• Measure & mark the intersecting wall location.
• Drill 4" holes at rebar heights, or remove full foam at the cavity (as specified by the engineer).
• Attach the intersecting wall to the flanking wall using ZEE brackets at each block layer. Face the bracket downwards to avoid catching concrete overspill.

Screw ZEE brackets to ICF webs using 4x #8-1½" deck screws. On tall walls, use a strongback & kicker for the first 3 courses, with 2x4 strapping (42", 18" O.C.) attached vertically using #8-½" deck screws.

• Install the second course of ICFs, flipping over each corner to obtain a 16" offset over the joints below.
• Ensure the marriage line is located directly above the line below.
• Install horizontal steel in the web notch 1" away from the rebar in the layer below, allowing the vertical steel to weave in between the horizontal rebar.
• This offset applies only on the 2nd course, afterwards all rebar returns to the second position.

• Attach Zevelers 8' on center with an extra pair at corners. Drill-adjust the wall to make it level and plumb.
• Check corner distance and strap four 36" 1x4s across the marriage line in the middle of the ICF. If not in the middle of the ICF block, this will affect Zont placement.
• Foam the ICF to the footing, 16" length, 48" on centre, both sides, to hold the base in position and prevent uplift. 10 minutes later, foam all of the wall to prevent uplift.

Block Leveling

Level the first two courses using adjustable side supports (Zevelers) at 8' nominal spacing, attached to the ICF webs and glue-foam tacked in place. Screw a 2x4 corner guide at each corner, run a string line between them, and drill-adjust each Zeveler for level before setting the blocks.

• After four courses of Nudura, install Zonts at the top of the fourth block and the bottom of the second with two #8x1-1/2" deck screws. Place Zonts two webs from corners and 5' on centre.
• Place straight 2x4 walers in Zont saddles, scab a 4' 2x4 over joints.
• Keep bracing (kicker) spacing along the wall to 6' max.

Zont Bracket Placement

Attach a minimum of 2 Zonts for walls up to 8' tall, secured to the web with 2x #8 1.5" wood deck screws (the third hole is a backup if one screw strips). 

• Screw Zuckle to the kicker, attach to the base of the handrail upright.
• Double stake the kicker to the ground.
• Screw-attach the Zat bracket 3' from the top of the wall.
• Install 2x10 catwalk plank(s) as required. Loosely attach so the wall can still adjust.
• Double check plumb & secure before tightening up bracing.

Zont Bracing System

The Zont bracing system uses the ZONT® waler bracket, the ZAT® walkway bracket, and the ZUCKLE® wall aligner (with drill adapter). 

• Using the catwalk, build the balance of the wall.
• Thread the vertical steel between the 1st & 2nd course as per the engineering details.
• Screw 1x4 (or 2x4) blocks on each corner, run a string line between them, then adjust each Zuckle to align the wall to each string-line.

Horizontal Rebar Spacing (18" O.C. vs 12" O.C.) 

Floor Ledger Support

For floor ledger support: cut a nominal 4" x 4" opening in the ICF for the anchor bolt hook (final size to the structural engineer's specification), and centre the ICFVL over the web, securing it with a deck screw before the concrete pour. Anchor bolt type/spacing and ICFVL spacing follow the structural engineer's specification. 

With corners, catwalk, kickers (w/ Zuckle), metal stakes, and Zat brackets as required all in place around the perimeter, the wall is ready for the concrete pour.

• Order ICF-mix with a 5-1/2" to 6" slump, maximum aggregate size 1/2" and compressive strength required by the structural engineer.
• Order a pump with a 3" reducer to minimize flow into the forms.
• Place concrete in 3' lifts.
• Vibrate with a 1" or 1-1/4" head, do not over-vibrate in one location — slow in, fast out.
• ICF corners are vulnerable — pour into each corner and don't vibrate the corner itself.
• After the pour, re-check the wall with a string line for final alignment.

• Dismantle bracing and put in appropriate totes ready for pickup.
• Return unused and undamaged ICFs to VancouverICF.

Rental Bracing

A typical rental bracing set includes: 20x Zont, 8x MDHD (4 pairs, as required), 10x Zuckle, 14x Zee, plus a Zote, MidZote, Lo-Zote and Red Totes, and Zats (supplied in top & tailed pairs).

Typical Details (Reference)

These details are advisory only; for the full site guide, download the complete PDF guide.