City of Lawrence

Building Code Board of Appeals

February 8^th, 2007 minutes

MEMBERS PRESENT:	Lee Queen - Chairperson, Mark Stogsdill, Janet Smalter John Craft
MEMBERS ABSENT:	Mike Porter
STAFF  PRESENT:
Guess Present :
Ex-Officio	Adrian Jones

Meeting Called to Order 11:55

Review minutes from Board meetings 11-30-06, 12-21-06, 1-11-07

Queen made a motioned to approve minutes from board meetings of

11-30-06, 12-21-06, and 1-11-07. Second by Smalter motion passed 4-0.

Complete review of IRC draft ordinance

The Board held a brief discussed on the amendments to table N1103.2.1 exception 2.

Craft was concerned the wording of the amendment requiring attic flex duct to be covered by 50% of blown in insulation was not specific enough to guarantee adequate coverage by blown in insulation.  He stated that because heat rises the wording should specify the top portion of the duct be covered.  When he read the ordinance he understood at least 50% of the run of pipe had to be covered completely.

Stogsdill stated that he thought that Porter’s calculations indicated that if the overall duct had 50% of the surface area covered by blown in insulation that would equal the R-8 value. The top of the duct did not have to be covered.

Queen and Smalter agreed.

Jones stated that surface area of the flex duct included the area connected to the main trunk which would be included in the calculation. If the portion of the duct connected to the trunk was completely exposed and the transition to the terminal was completely exposed then the center portion would have to be completely covered with blown in insulation to meet the 50% rule. Jones stated that he believes mechanical contractors will all switch to R-8 flex duct rather than spend the extra time trying to configure the ducts to allow coverage by blown insulation.  

Queen said that on a 14 or 15 foot run if 2 feet coming off the trunk and 2 feet attached to the boot were exposed and the rest is completely covered by blown in that would meet the 50% rule.  Either way it’s going to be a call by the inspector.

Stogsdill stated that another way he’s seen attic ducts insulated is to build a box around the metal ducts that would contain the blown in insulation.

Queen noted that all flex ducts are going from the current R-4 to a minimum of R-6. He believes the draft ordinance language will work.

Stogsdill said that he can see there may be an interpretation issue but as long as the inspector understands that 50% of the total area needs to be covered then he sees no problem with the wording.

Jones said that the City does not deal with a large number of mechanical contractors. He believes after a short time the contractors will correctly interpret the provision.

Jones explained the amendments for sections E3501 through E3508 were provided by the Electrical Board and included in the draft.

Noting section E3501.6.2 Stogsdill asked if there was currently a limit on the distance the disconnecting means from the point of penetration into the building.

Jones replied the amendment is currently included in the Electrical Code ordinance. The code was amended to limit the distance from the nearest point of entry and not leave that up to the interpretation contractor.  

Queen said that he does not agree with code provision that requires an outlet within 25 feet of an AC unit.

Jones said that was to limit the use and length of extension cords.

Queen stated show him a service person that does not have a 100’ extension cord on their service truck. Service technicians will have to use an extension cord whether it is a 25 ft. cord or a 100 ft. cord.

The Board discussed section R404.1 Foundation and Retaining walls.

Jones stated that this section has been revised for the 2006 IRC. The new provision requires a combination of reduced anchor bolt spacing along with blocking of floor joist to counteract unbalanced load pressures on foundation walls by expansive soils. Jones said that he sees this prescriptive method very similar to the narrow panels adjacent to garage doors. A builder could use the prescriptive method or BSD could accept an engineered design.  The City could accept a design which incorporates most expansive soils.

Queen asked who would determine the types of soils.

Jones replied that expansive soils are predominate here in Lawrence, especially out west in most of the newer subdivisions.

Queen said that most builders will put in deadmen or buttresses to counteract those pressures. (A deadman is term for a short section of foundation wall, which is perpendicular to the main wall, installed to resist lateral movement.)

Jones said that he has seen quite a few foundation failures in older homes that were a result of expansive soils.   

Queen said that he has seen new homes that were back filled too early or backfilled carelessly. There are certain things that just don’t work.

Queen said he was also concerned the code required three joist spaces blocked.

Craft asked Jones his opinion on this section.

Jones said that he would be against amending a prescriptive provision of the code based on an engineered design.

Stogsdill agreed. Porter could better address the engineering aspects of this code section. 

Queen suggested the code be amended to add an alternate design of so many buttresses per linear foot of foundation wall.

Jones stated that an engineer would have to stamp off on that design before the City could accept it.

Queen said that his experience showed that the design worked because his company has never had any problems using that design.

Stogsdill asked if Queen he put the buttresses inside or outside of the wall and how much reinforcement he used.

Queen replied that he usually put the buttresses on the outside for usability reasons and rebar on 2 foot centers.

Stogsdill said that it his understanding that unless the reinforcement is spaced on 1 foot centers it is not even calculated by engineers.

Craft asked if it was correct to say that this code section allowed for the foundation and floor diaphragm to work together to resist soil pressures.

Jones said that was his understanding of the provision.

Stogsdill stated the other option was to design foundation walls as a retaining walls. He described how a wall could be designed and in what type of application it could be used.      

Queen said that he thinks there should be an alternative to the code provisions.

Smalter asked how the garage portal was handled.

Jones replied the Lawrence Homebuilders submitted a design that was approved by the City and all the builders used it.

Stogsdill asked Queen if he was proposing that the Board come up with a standard or Queen provide one.

Queen asked what would be the reason for the amendment. He has not seen or heard of any problems with foundation walls failing.

Jones said that problems with new foundation walls are not widespread but they happen.        

Queen said his concern was the amount of blocking required. He thinks most of the problems are associated with poor practices.

Smalter noted section R404.1.7 required the wall to be properly supported before backfilling.  

The Board discussed foundation wall bracing practices prior to backfilling. 

Craft asked Queen if he thought the homebuilders would want to provide a standard that would be supplement to this chart that could be amended into the Code as they had with the garage portal design.

Queen replied he thought the HBA would be willing to provide a standard and spread the cost out over 250 members as opposed to complying with this prescriptive element. Queen said he would discuss it with the membership.

Craft said that it would have to be a chart that accounted for all soil conditions and wall heights.

Jones explained section 302.1 required that construction projections, openings and penetrations of walls not extend into the minimum 5 feet fire separation distance from property lines. Any projection into that distance needed to be rated for 1 hr construction. An exception allowed projections of only 12” without a 1 hour rating. Jones said that meant soffits and fireplace, the most common projections, had to be of 1 hour construction. The old code was 3 feet.

Smalter asked about window boxes.

Jones replied not only would the wall of a window box but the glass would needed a 1 hour rating. There were no openings permitted less than 3 feet from the property line.

The Board discussed different types of wall ratings and projection types that would comply with the new ordinance.

Queen said that he saw this as a design issue.

Craft made a motion to adjourn second by Stogsdill, Motion passed 4-0.

Meeting Adjourned