Frequently Asked Questions
1. Q. Can tapered systems be priced by the square?
A. No, (click here for explanation)
2. Q. What is the difference between Average R-Value and Minimum R-Value?
A. Minimum R-Value, the thinnest point in a taper system occurs at one location only in each system. Average R-Value is the measure half-way between the minimum and maximum r-value in the taper system. Average R-Value is the quantity that should be used to calculate real heat transfer through the entire taper system.
3. Q. What is compressive strength as it relates to Polystyrene Insulation?
A. Compressive strength is the weight, usually expressed in pounds per square inch, required to compress polystyrene to 90% of its original thickness.
4. Q. What is a Cricket?
A. A cricket or saddle is a pyramidal diamond shaped device used to divert water around an obstruction such as a skylight, HVAC unit, chimney, etc; or to divert water along a parapet wall to the drain sump or through-wall scupper.
5. Q. Would you recommend building a cricket out of wood?
A. No, wooden over build crickets can trap moisture even when vented. Trapped water vapor will encourage dry rot damaging the roof system, roof substrate, and possibly the building structure. Crickets constructed of foam insulation leave no void where moisture can collect.
Wood structure affected by dry rot
6. Q. What is the industry standard for slope on a commercial roof?
A. 1/4” per foot slope has been the minimum industry standard for some time. In most locations it is now a code requirement.
7. Q. Does T.D. do site visits / roof walks?
A. Yes, (see Our Services for more information)
8. Q. How many licks does it take to get to the center of a Tootsie Roll Pop?
A. Nobody Knows!
9. Q. I received a quote with a Budget Price. What does a Budget Price mean?
A. When a Budget Price is given for a project it refers to a ball park figure for what is shown on the quote drawing. Typically these budgets are provided when incomplete or inaccurate information is given at the time of a quote. Actual price may be more or less than the Budget Price when complete or accurate information is provided.
10. Q. What tapered insulation material does Tapered Design have in stock?
A. Polyisocyanurate, Perlite/Fesco
(polystyrene insulation can be provided, but is not a stocked item)
11. Q. What is the lead time on material availability?
A. Polyisocyanurate: same day
Perlite: same day
Expanded Polystyrene: 1 week
Extruded Polystyrene: 1 week
(Time availability given when material order is placed)
12. Q. What does it mean when the T.D. quote sheet says, "No Base Layers"?
A. Base Layers are thermal barriers, vapor barriers, cover boards, flat thermal insulations specified in the roof system. Typically these layers are not considered a part of a taper system.
13. Q. What is a multiple layer cricket?
A. Typically a cricket is formed of one layer taper system. On occasion one or more layers/taper systems must be employed to counter a steep roof slope. (example: 2 layers of 1/2" per foot slope cricket = a 1" per foot slope cricket.)
14. Q. How much time is required for standing water to be considered a pond?
A. 48 hours when sunlight is present.