Document dnGvb01G5r344xp6q5wLLDgY5

ouijixu.tjxiuxao. Dona Id J. Smith. 3^91 Connaught Avenue Montreal 232, Quebec,, Canada Tel.: (51I) 43 -33-24 PLAINTIFF'S EXHIBIT BIR-854 Progress Eeocrt June lo, 1972 INVESTIGATION OF CRACKING OF ASPHALT SHINGLES IN THE WEATHER To: Lir. Carroll A. Houan cc: Messrs. N. K. Price A. 1C. Powers L, N. Heaver D. S. Frasier A. 3. Iiei:a 3. N. Sinicov.'sisL BIRD 013346 Introduction Mr. N. K. Price accompanied the waiter on e:caruina tion or roofs in Florida, South Carolina, and North Carolina. In addition, the writer,examined roofs in Atlanta, Ga. The cooperation of area salesmen has teen wholehearted and essential. Mr. Price has collaborated in this progress report. The detailed reports appended show the salesmen involved and the areas covered. BIRD 013347 Surma r; ox observations Frou Tar.ua, Florida, north to Elisabeth City, if. (J. , all seal down chin les, loth of Bird and of ccrpetitive manufac ture, are cradciir h-risontally, the start occurinv two and one half to five ,, ears after exposure. The ora oleins parallels the butts of the sliins3.es at a distance of one half to two and one half inches bclov; the ovorlyiny shin.les. This is about one half wa; between where the exposed butt is held by adhesive and by the first row of nails. On one job, one course of shin gles was exposed for five inches at one end of the roof, taper ing to three inches at the other; the o:.aoidny gradually approached the butts of the overlyiny shinnies as the exposure decreased and finally disappeared under the cverlyiny shinvies. Self sealed and hand sealed'shin les hehavedi similarly. Ho horizontal cracld.no; of this type was observed on unsealed shin,les. The severity of ora chin appears to be affected b.. nan;; fac tors. heavier weijht shin les developed wider evades, and lighter weights have finer crachs. Da rice r colors have severer era chin than ?.ijhter ones of similar exposu:.e. Lower slopes developed more severe craclriiu. j\t each'particular location the nest advanced eracbin developed on low; slopes on the southern to south-western exposures and was worst in Florida, least in Atlanta. Ora olein, ri ht throw h the felt has occurr ed in as little us four cars, where all fact rs were unfavor able. Failure, i.e., splitting uhroujh the full thiehness of the shin les, has occurred in as little as five . ears. It was noted that Lira PK coat in. s arc very -viable. One Johns-hanville exposure was si.iiarl; friable. i lar.e area of blade Firescreens, exposed in Florida on an apartment ocu.'l-x at about three and one b.alf inches per foot slope o'er thoes . ears has failed coupletel. and will have to be`replaced. Vertical cracicin. to the point of failure, particularly severe in sow c seed lines, was associated with the horizontal era chin ; on sea3.0' shin los. Jraze t. ;.o -ru chin; de veloped w:ith a-e in unsealed thiclr-hatt shin.les, ' vf was not critical. dwell!:: -;f felts was fuirl; encral, ..ore noticeable on mar..: --" ^ s a no. *. a us. BIRD 013348 Tentative Conclusions 1. Life expectancy for Marie 25 shingles is much be low the 25-year guarantee period, throughout the area surveyed. 2. Life expectancy for Kindseal and Kind seal Jets is likely to be less than the 15-year guarantee oeried, particul arly in the southeast. 3. Competitive shingles are behaving similarly. 4. Shingles sealed by factory-applied adhesive and by roofapplied strips of adhesive are failing similarly. 5. -Non-sealed shingles are not subject to horizontal type cracking. 6. Brittle coatiny may be contributing to the hiyh rate of deterioration of sealed-down shingles. 7. Low proportions of saturant are contributing to swelling and shrinkage due to moisture absorption. This may be associated with the use of kijher weight and variable kerosene felts. Tentative Suggested Failure Mechanism The diurnal and seasonal increases and decreases in tempera ture and moisture cause shingles to expand and contract. When the exposed portions of these shingles are held by two hori zontal lines of restraint, the expansion results in a bowing upward between the lines. This results in sufficient strain to cause minute cracks. The cracks loosen the ranules immediately adjacent to them, increasing the rate of attack by the sun. The cracks widen. Water reaches the felt. The extent of the expansion-contraction cycle increases. Perman ent contraction occurring with each drying period finally results in sufficient strain to pull the felt apart. The 'thicker the coating, the greater is the strain at the surface for any degree of flexing, and thus the more rapid the crack ing and subsequent failure. Recommended Action Further invest! ation appears to be imperative. BIRD 013350