Frequently Asked Questions
Rim Board (RB)
1. Does the installation of RB require any special tools or skills?
No. The concept is the same as for conventional rim board. However, the I-joists can be installed faster because the modular receptacles are pre-positioned.
2. Do you have to use a framing square to assure vertical alignment of I-joists?
No. The receptacle holds the I-joist in perfect alignment position.
3. If I use the RB, will it cost more?
Not usually. Normally, any minimal extra cost incurred for materials is offset in labor savings.
4. How does RB help with safety on the jobsite?
Locking the I-joists into the receptacles reduces the chance of rollover before and after the sub-floor is installed.
5. How much improvement can I expect in lateral shear values?
Preliminary independent testing indicated the RB alone could increase the lateral shear up to 15%. However, any specific value attributed must be provided by the project engineer.
6. Can RB be used on the ends of I-joists in a cantilevered floor system or as sub-fascia on I-joist rafter tails?
Yes. The receptacles hold the cantilevered ends of I-joists in perfect alignment without twist or bow.
Rim Insulation (RI)
1. Should I expect any complications installing the RI at the same time of the positioning and placement of the I-joists?
No. It is easy… and on the main floor over a crawl space, you avoid the unpleasant and inefficient job of crawling beneath the floor to install insulation at a later time. Merely position the panel after each I-joist is placed and toenail the inside bottom edge of the panel to the plate below.
2. What is the R-value for RI?
The installed R-value for standard RI designed for a 2x6 plate is R-13. Greater values are available to meet codes in select markets.
3. What are the advantages for using RI in new construction?
There are numerous reasons for use… better fit for less leakage, easier and faster to install, and reduces the potential for mold and rot on perimeter structural components in the floor system. There is always potential for moisture related problems in a crawl space... and certain blanket-type insulation can become saturated with condensation and hold moisture for weeks. Eventually “wet blankets” could result in mold and/or rot of adjacent wood components. In contrast, foam insulation does not absorb moisture.
4. Can RI be used as modular panels on conventional rim board for proper spacing of I-joists?
Yes. Either the RI or IB can be used interchangeably, but frequent measurement should be conducted to monitor modular “shrink and creep”. Obviously, some of the lateral shear values may be lost without the use of I CHOICE Rim Board.
5. Can RI be use to replace existing insulation?
Yes. The RI is available in 12’ lengths (without flange corners) to CTS on site for customized installation.
Insulated Blocking (IB)
1. How does IB installation vary from the standard Rim Insulation?
The installation is the same... Quick, Easy, Builder friendly. However, the structural benefits for the IB are numerous.
2. As a framer, builder or dealer, how can I utilize the IB to obtain advantage in the market place?
There are a number of ways, but two have particular appeal. First, the IB can provide a double Rim Board, equating to nearly doubling the vertical load capacity. This can be critical for adding an additional floor(s) to low-rise structures. Also, IB provides opportunity for the trades to standardize inventory sku’s by establishing an I CHOICE Premium Floor System… establishing and driving the 80:20 Rule. This can be actualized by using IB with a 19.2” OC I-joist spacing "system", thus saving one (1) I joist every eight lineal feet (vs. 16” OC spacing). Standardized 19.2” OC spacing could result in reduced sku’s... smaller inventory... higher turnover... less investment.
3. Can IB be used with RB and SB’s to create a total Building System providing advantage in high wind shear and seismic geographic regions?
Potentially yes. Confirm with your project structural engineer how additional nailing and other hardware can combine with these Products to achieve the values you require.
4. How can I use IB when the spec calls for 2” foam panels to be laminated to the exterior of basement walls and foundations?
The IB make this an easy solution to a complex problem. You merely cantilever the I-joists so that the primary Rim Board extends out 2" over the foam insulation around the perimeter of the foundation wall. The primary Rim Board then becomes the basic platform for attaching the sidengs and sheathings, but does NOT support any vertical load. When IB is installed just inside the Rim Board at the same time as the wood I-joists are installed, the IB assume the vertical load. The structural component of the IB becomes the total load-carrying component for the structure. If the design requires more load capacity than provided by a single IB panel, simply combine additional IB panels to achieve the desired rating. Problem solved.
5. Can IB be used to retrofit insulation and certain structural circumstances in existing structures?
Yes. When used with SB’s, 12' lengths of IB (without flange corners) can be CTS on site and customized to fit between specific I-joists.
Blocking Panel (BP)
1. Can I use BP’s as end blocking to connect the parallel rim board to the adjacent I-joist to link the two together and provide additional stability?
Yes. Merely trim-to-size one notched side of the BP and nail directly to the inside face of the rim board... and the other side to the web of the adjacent I-joist.
2. Can I use the BP to carry the vertical load over the plate for a cantilevered design?
Yes. The BP will fit perfectly between the I-joists and support the load. Add additional BP’s to accomplish design load capacity.
3. Do BP’s work between the I-joist rafters as insulation baffles/blocking to control airflow in attics and roofs?
Absolutely. They are designed to perform in that function. The amount of “V” removal of the BP top edge to control airflow must be calculated in advance.
4. Could BP’s be used to add more vertical load capacity to build additional floor in all wood construction?
Potentially yes. Simply add more BP’s to the lower floors and reduce the number of BP’s with the higher elevations. Verify local code requirements and have the project engineer determine limitations.
Support Block (SB)
1. Why should I use a SB instead of a 2x4 squash block?
First, the SB is fastened with nails through the web instead of the flange, thus preserving the flange from nailing damage. Flange damage can create a series of problems including “red flags” and work stoppage resulting in major cost for replacement. Also, the SB is machined perfectly square and to the correct length, which is an absolute requirement for performance.
2. Why should I use a SB instead of web stiffener?
SB’s provide additional structural attributes while being easier and quicker to install.
3. Are there any complications in using the SB as a nailing platform for securing fascia?
No. It is the perfect solution for attaching roof fascia to the I-joist rafter. Simply attach a SB to the rafter tail to get a "solid" end for firm nailing attachment.
4. If I use the SB to increase the load carrying capacity of the assembly, what is the rating?
For vertical loads, SB’s are used in pairs on both sides of the I-joist.(See Product Bulletin for specific load ratings).
5. How do SB’s compare with 2x 4’s in load carrying capacity?
SB’s and 2x4’s both exceed the compression strength of the plate… the weakest member of the floor assembly. SB’s used in tandem on both sides of the I-joist exceed a single 2x4 squash block.