What is the typical Interior finish on an ICF?

All build­ing codes in the USA and Cana­da spec­i­fy that plas­tic insu­la­tion (EPS) must be cov­ered by a ther­mal bar­ri­er equiv­a­lent to 15 min­utes of fire pro­tec­tion in hab­it­able spaces. This is achieved with ½” gyp­sum board or an equiv­a­lent mate­r­i­al. Fox Blocks has spe­cif­ic fire test­ing that proves reg­u­lar ½” gyp­sum board with reg­u­lar dry­wall screws fas­tened into the plas­tic webs remains on the wall for the required 15-minute time peri­od.

What exterior finishes can be used on an ICF?
Fox Blocks are com­pat­i­ble with all exte­ri­or fin­ish mate­ri­als and sys­tems – sid­ing, stuc­co, mason­ry veneer, sim­u­lat­ed stone, etc. The attach­ment of cer­tain exte­ri­or fin­ish­ing sys­tems is rec­om­mend­ed with exte­ri­or grade screws fas­tened into the exposed or con­cealed webs.
How do I determine which size ICF to use?

ICFs pro­vide a rein­forced con­crete wall which is designed to spe­cif­ic engi­neer­ing prin­ci­ples. Typ­i­cal res­i­den­tial con­struc­tion, per the applic­a­bil­i­ty lim­its in the build­ing code, allows walls 10′ (3 m) high or less between lat­er­al sup­ports (floor and roof con­nec­tions). Below grade walls must have a min­i­mum 6″ (150 mm) con­crete core. In some regions, an 8″ (200 mm) con­crete core is the min­i­mum allowed thick­ness for below grade walls.

The 4″ (100 mm) form can­not be used below grade as a foun­da­tion wall. The 4″ (100 mm) form may be used for above grade walls up to a max­i­mum of 10′ (3.0 m).

The 6″ (150 mm) form, above grade, is lim­it­ed to approx­i­mate­ly 14′ (4.2 m) in height. Walls high­er than 14′ (4.2 m) must use an 8″ (200 mm) or larg­er form.

Typ­i­cal res­i­den­tial con­struc­tion will use 6″ or 8″ con­crete core size blocks. Project spe­cif­ic engi­neer­ing may allow for some core thick­ness to span ver­ti­cal­ly high­er than these pro­posed guide­lines.

What is the R-Value?

The clear R‑Value of an Fox Blocks is R22, how­ev­er cur­rent Ener­gy codes rec­og­nize the lack of ther­mal bridg­ing in an ICF and the con­tri­bu­tion of the mass con­crete on the influ­ence of the ther­mal per­for­mance. Whole wall cal­cu­la­tions indi­cate a Fox blocks wall assem­bly pro­vides an R24 rat­ing.

The con­tin­u­ous dou­ble lay­er (inside and out­side) of insu­la­tion, the elim­i­na­tion of ther­mal bridg­ing and min­i­mal air infil­tra­tion through the mass con­crete wall assem­bly, allows Fox Blocks walls to per­for­mance in the high per­for­mance wall assem­bly cat­e­go­ry. Com­plet­ing the enve­lope with ener­gy effi­cient win­dows and doors and roof insu­la­tion, Fox Blocks homes can eas­i­ly meet and exceed ener­gy code require­ments and exceed the min­i­mum require­ments for Ener­gy Star and Ener­Guide. A Fox Blocks struc­ture requires 44% less ener­gy to heat and 32% less ener­gy to cool.

When is a Taper Top form required?
Taper Top forms are specif­i­cal­ly designed to pro­vide a larg­er bear­ing sur­face along the top of the wall. Typ­i­cal­ly, the increased bear­ing sur­face may be used to sup­port mason­ry, floor or roof loads. Taper top forms are used in the tran­si­tion from ICF to wood frame con­struc­tion and the taper top form would be the top form on the wall.
Can you vibrate or consolidate the concrete in ICFs?
Yes, con­sol­i­da­tion of the con­crete is one of the key ele­ments in the place­ment of con­crete in an ICF wall. Fox Blocks rec­om­mends inter­nal vibra­tion with a pen­cil vibra­tor, quick­ly in and slow­ly out.
Can I leave Fox Blocks forms exposed to ultraviolet rays for an extended period (months)?
Yes, but you will notice a light dust­ing on the sur­face and a yel­low­ing dis­col­oration of the forms. This does not indi­cate any detri­men­tal effects to the ICFs. We do sug­gest, that if the exte­ri­or fin­ish is not going to be installed with­in around a 3 month peri­od or more, the forms be pro­tect­ed from UV rays by installing a tem­po­rary build­ing wrap type mate­r­i­al. The pow­dery film must be removed with soap and water before the appli­ca­tion of a syn­thet­ic stuc­co fin­ish or water­proof­ing mem­brane.
Is burning EPS toxic?
Test reports con­duct­ed by the Nation­al Research Coun­cil state: The max­i­mum tox­i­c­i­ty index obtained from the com­bus­tion of poly­styrene was of the same order as that of wood.” Fox Blocks ICFs have been test­ed to meet build­ing code require­ments for flame spread rat­ings, smoke devel­op­ment and tox­i­c­i­ty
Is the Fox Blocks ICF product ‘LEED’ rated or certified?
Prod­ucts are not rat­ed or cer­ti­fied under the LEED pro­gram. The over­all build­ing is eval­u­at­ed and assigned a LEED rat­ing. In the selec­tion of build­ing mate­ri­als for a LEED design, Fox Blocks have many ben­e­fits that can enable, enhance or direct­ly con­tribute toward LEED points for the project.
How much will it cost per square foot to build an Fox Blocks ICF home?

Build­ing with Fox Blocks ICFs pro­vides you with a high per­for­mance wall sys­tem for the foun­da­tion and above grade walls. Build­ing any high per­for­mance home, with either ICFs or con­ven­tion­al wood fram­ing, has many fac­tors that define the end cap­i­tal costs.

What addi­tion­al mate­ri­als and labor are required to make a con­ven­tion­al foun­da­tion equiv­a­lent to an Fox Blocks ICF foun­da­tion which exceeds ener­gy code require­ments in most loca­tions? Con­ven­tion­al wood fram­ing requires con­sid­er­ably more mate­r­i­al, insu­la­tion and atten­tion to air seal­ing to make it qual­i­fy and per­form as a high per­for­mance wall. All of this, for con­ven­tion­al con­struc­tion, adds mate­r­i­al and labor costs to the over­all project. Fox Blocks ICFs pro­vide a sim­ple method to build high per­for­mance walls that pro­vide ongo­ing ben­e­fits from the high insu­la­tion val­ues and mass con­crete walls that are ener­gy-effi­cient and pro­vide cost sav­ings for the life cycle of the build­ing.

Com­par­ing cost per square foot between con­ven­tion­al con­struc­tion and ICFs for a high per­for­mance build­ing, is like com­par­ing apples to oranges. To devel­op con­struc­tion costs, more detailed infor­ma­tion is required, for instance the num­ber and size of open­ings, the shape and size of the home, the region­al costs for mate­r­i­al and labor, etc. If you have a project you’d like us to review and pro­vide a mate­r­i­al esti­mate, Fox Blocks would be hap­py to have one of our rep­re­sen­ta­tives con­tact you. Please com­plete and sub­mit a lead infor­ma­tion sheet on the web­site or call Cus­tomer Ser­vice.