Comment on Opinions or experience with APEX block? by DC33

Comment on Opinions or experience with APEX block? by DC33 I have used both Apex and Rastra type ICCF blocks. Some manufacturers offer various wall thickness, so I will only compare the 10” wide block. Most of my outlying landscape walls use the Apex while the main structure was constructed with the Rastra or similar. The basic mix of each is quite similar and the post (vertical) and beam (horizontal) holes are approximately 6” diameter. Both use rebar and concrete according to the SE specifications. Therefore I will first give the main differences. The Apex is roughly 10”W, 15”H, 48”L with a weight of approximately 50 lbs. The 3 post holes are 15” on centers (one being in the center) with the beam hole running through the center length. The block ends, top and bottom are contoured with an interlocking design to assist alignment. Apex pros:Easy to handle, stack and align.Plenty of surface area for glue.Apex cons:Requires rebar to be placed during assembly (beam hole only accessed from ends).Corners must be planned well ahead of assembly.The Rastra block is roughly 10”W, 15”H, 120”L with an approximate weight of 145 lbs. The post holes are on 15” centers with half diameter on each end (butting two blocks creates a 6” post hole at the joint). The 6” diameter beams are achieved when one block is placed on top of another (the top and bottom of the block have a 3” radius running the full length to create the 6” diameter beam).The ends, top and bottom are not interlocking. (There are other manufacturers using this design, but in shorter length.)Rastra pros:Blocks are heavy and cumbersome, but can be easily cut.Rebar can be shaped and simply dropped into the radius after each block course is in place, even in curved walls. Special vertical corner blocks are available.Flat panels can be used in place of blocks if a concrete roof is desired.Rastra cons:Blocks are heavy and cumbersome.Care in block alignment is a must (just like a cinder block wall).Additional care should be taken when gluing the blocks together.Now for the good part: Although, pure foam has a greater R value, ICCF has a fire rating of 4+ (only because the ICBO didn’t like issuing a “5” rating … my opinion). I have thrown some of this block into a fire pit and also held an oxy-acetylene torch on the block for 10 seconds with NO effect. I heated a protruding anchor bolt red hot to bend it at the wall surface … again, no problem. I have seen plenty of foam go up in smoke … not something to breathe in! Termites do not even nest in ICCF (they will chew out 100% foam). So, my main purposes for choosing ICCF products were fire and termites. I built in the SW desert where typical utilities for a 2,000 sqf house run $300 to well over $500 / mo during the summer heat (April thru October). My total utilities for last July and August 2019 (the really HOT months) were $125 and $132 respectively. That is with a two-year old 3.5T LP gas-pack AC. My previous AC unit was only 2.5T, but ran 24-7 during the two week stretches of 115 degrees. During the winter I use two or three portable oil-filled radiators for heating. As electric is currently cheaper, the LP only gets used as secondary. Total winter LPG use including BBQ is less than 200 gallons. Currently, my windows have no special tint or shading. That will be changing.I have approximately 2,200 sqf, 10’ ceilings and a 250,000+ lb concrete and rebar roof (no attic or crawl space). This puts a different perspective on who’s ICCF you use. Rastra is one of the very few that offers flat panels for solid concrete walls (most likely required for concrete roofs). My roof is currently covered with DuraLast and is fully walkable. I can take my shirt off, lay on that roof in 112 degree high noon and not burn … sweat, yes, but no burn! There is an additional expense for a concrete roof in two ways. You will need a bit more concrete in your floor plus rebar to support the shoring material which will need to be in place for a month till the roof cures. The shoring material may cost you more than you expect, check your local resources. 20 years ago it cost me $10,000 for the shoring material, setup and tear-down. But, I estimate it has saved me $500 a year in cooling and heating costs vs a conventional roof. Choosing a concrete roof does restrict the room size due to span limitations. All of my exterior door frames (and some interior) are commercial steel … no wood. This in no way makes my house a bunker (I have designed those), it is mainly for fire and termite protection. I also use metal frame windows, SW

desert UV eats vinyl for lunch. Also, all of my ventilation is underground, below the concrete slab (no basement). That is a plus during the summer as that air stays cool and can be accessed by using only the circulating fan on the AC unit. An additional system that works well is an economizer which allows outside cool air to be brought in vs running the AC compressor. My AC unit is ground mounted. Things I would do to improve would be use 3/4� conduit as a minimum for all electrical (I used 1/2� in many runs). I do NOT suggest stuffing your wiring into the ICCF! Go ahead, try to pull that wire out!DC33