Do I need an engineer to design and stamp Fox Blocks building plans?
Fox Blocks are list­ed in the build­ing codes (IRC- Sec­tions R404, R611 or NBCC Part 9) with spe­cif­ic applic­a­bil­i­ty lim­its for res­i­den­tial con­struc­tion. If the project meets the applic­a­bil­i­ty lim­its with­in the build­ing code, a Pro­fes­sion­al Engi­neer may not be required (depen­dent on local build­ing depart­ment require­ments). A build­ing offi­cial has the right to request engi­neer­ing and in some regions all projects require a professional’s stamp. For any projects that exceed the applic­a­bil­i­ty lim­its, a Pro­fes­sion­al Engi­neer is required for the struc­tur­al design. Check with your local build­ing depart­ment.
Do you need special code approvals to build with Fox Blocks ICFs?
No, ICFs in gen­er­al are cov­ered in the build­ing code and Fox Blocks ICF has a prod­uct eval­u­a­tion report that con­firms the prod­uct and appli­ca­tions meet the require­ments of the respec­tive build­ing codes in the USA and Cana­da. These reports are avail­able on our web­site.
How do I apply traditional stucco to an ICF?

Tra­di­tion­al stuc­co has a thick cemen­ti­tious base, typ­i­cal­ly installed over a met­al lath. The met­al lath is fas­tened direct­ly to the Fox Blocks webs with screw or sta­ples.

Is installing ICFs a DIY project?
Fox Blocks rec­om­mends that all installers using Fox Blocks ICFs com­plete a Fox Blocks train­ing pro­gram to ensure they have a bet­ter under­stand­ing of the basics. How­ev­er, for first time installers, it is pre­ferred that a Fox Blocks trained, expe­ri­enced installer inspect the instal­la­tion pri­or to place­ment of con­crete and assist in the place­ment of the con­crete, as they are famil­iar with work­ing with con­crete and can ensure the build is struc­tural­ly sound and safe and the walls are con­sol­i­dat­ed prop­er­ly, built straight and plumb.
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.
What fasteners are recommended for ICFs?

Fox Blocks has con­duct­ed numer­ous fas­ten­er tests for pull-out strength and shear capac­i­ty for var­i­ous fas­ten­ers – screws, ring shank nails and sta­ples into the plas­tic webs. The rec­om­men­da­tion for inte­ri­or and exte­ri­or appli­ca­tions of fin­ish mate­ri­als is for the use of screws which pro­vide the best hold­ing capac­i­ty into the plas­tic webs or fas­ten­ing strips in the forms which are iden­ti­fied on each block.

The EPS insu­la­tion does not pro­vide any hold­ing capac­i­ty for fas­ten­ers.

What size and how much steel reinforcement is required in an ICF?

Fox Blocks walls are designed as rein­forced con­crete walls, with steel rein­force­ment bars spec­i­fied to be installed ver­ti­cal­ly and hor­i­zon­tal­ly, as the walls are built. Typ­i­cal rein­force­ment bar sizes used are #4 or #5 (10 m or 15 m).

What do termites do to the foam?
EPS pro­vides no nutri­ent val­ue and is not a food source for ter­mites. If left exposed, ter­mites may tun­nel into the foam in search of fibrous food. When build­ing, in a heavy ter­mite infes­ta­tion area, care is required in the detail­ing and con­struc­tion of the walls that will be in con­tact with ground, to pre­vent access to the foam for ter­mites.
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.