InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.Asphalt shingle cracks due to thermal splitting & defective product: this document tells readers how to identify & explain asphalt shingle cracking or thermal splitting, what causes shingle cracks or splits,and how to distinguish this product failure (which may be entitled to a warranty or class action claim) fromother roofing product failures or defects.We also provide a to this topic, or you can try the page top or bottom as a quick way to find information you need. FIBERGLASS SHINGLE CRACKS - Thermal Splitting Asphalt Shingle Crack & Tear Failures Described & Explained Fiberglass-based Asphalt Roof Shingle Cracking/Tearing/Splitting Failures' Thermal splitting,' or 'cracking' which in fact is in most cases actually atearing of the shingles is considered by experts to be the principal currentproblem with fiberglass-based shingles. We prefer the term tearing as a mostaccurate description of what's probably happening.
The other day I was surprised when I looked in the mirror and noticed a fine line running from my gum vertically down my front tooth. When I looked closely I noticed my other front tooth also had a faint crack in it! Both have small cracks that run from the gum down the tooth but don't connect. Fracture (From an Insurance Viewpoint) Terminology and wording used in insurance claims can make a big difference in whether a procedure is or is not reimbursed. Craze Limited to enamel. Tip of a dental explorer instrument cannot penetrate in.
Originally observed on thelightest-weight (15-year life) shingles this problem has now been found acrossall shingle styles, weights (life ratings), and we suspect, probably acrossmost or all manufacturers of this type of product.The thermal expansion of defective asphalt shingle product (common in the U.S. Across many manufacturers in the early 1990's) followed by thermal contraction when cool weather approached, explained the tear shown in the shingle in our photograph just above.See for a table of the coefficient of expansion of common building materials. We have not found a source defining the coefficient of thermal expansion of asphalt roof shingles - if you can provide that information.Does Thermal Splitting or Shingle Cracking Tearing Occur only in 3-Tab Asphalt Shingle Roofs?No. Thermal splitting or tears occur in both conventional 3-tab shingles (photo above) and also in laminated asphalt shingle roofs.Our photo (below-left) of thermal split/tear damage to a laminated asphalt shingle roof was provided by ASHI Home inspector.This unfortunate roof, inspected by Mr. Mauer in 2009, also suffered from granule loss (below-right) that in our OPINION looked like a defective product.The same roof also included a damaged shingle that looked like a cracking and granule loss problem combined, but we think this was a created at the factory during production - a bad individual shingle that is sometimes created when ends of shingle production substrate are spliced together. SeeWhat Does Shingle Cracking or Shingle Splitting Look like?Watch out: as we warn at if conditions prevented the home inspector from direct access onto the roof or at least a look from a ladder set against the roof edge, shingle damage, cracks, and splits such as that shown in own photo (at left) could have been difficult or even impossible to spot.
Inspecting the roof from the ground, even with good binoculars, can't show all roof damage types and conditions.We have observed a variety of torn or split asphalt roof shingles, illustrated by our photographs below. (Click to enlarge any image.).Horizontal Cracks & Splits in Asphalt ShinglesBoth thermal splitting and other shingle cracks and splits can also occur in a horizontal pattern as we illustrate in our photographs below.The horizontal cracking occurring in these fiberglass-based asphalt shingles resulted in complete loss of some of the shingles from the roof surface. The silicone caulk was placed by the owner during an attempt to 're-glue' the lost shingle tabs. But using our pen we pointed out additional horizontal cracks and tears developing in the next course of shingles just below. From a the ground the lost shingles looked like an isolated problem. An on-roof inspection told a different story.as we illustrate in our photo at left (Click to enlarge). What is the Cause of Thermal Splitting Cracks in Fiberglass-based Asphalt Roof Shingles?Our photos above demonstrate two classic thermal split patterns in fiberglass based asphalt shingles: vertical splits running straight up the roof (above left) and diagnoal splits following butt joints (above right).
It's possible that shingles made by some manufacturers do not meet the ASTM Standards for tear resistance. Even where shingles meet the Standards, it's possible that the standards themselves were defective. Mark Cramer, Tampa Florida, Mr.
Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211. home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI.
952 829-0044 -. Arlene Puentes Website: www.octoberhome.com , a licensed home inspector, educator, and building failures researcher in Kingston, NY. is an ASHI certified home inspector in Doylestown, PA.
Mauer can be reached by email to or by telephone at 287-884-4047. ', Ted Cushman, The Journal of Light Construction, May 1993, pp.
Used with Permission from the Journal of Light Construction. has generously given reprint permission to InspectAPedia.com for adaptations, quotations, or reproductions used at this website. All rights and contents of the JLC material are ©Journal of Light Construction and may not be reproduced in any form.Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair. Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the. Also see our.
Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10:, ISBN-13: 9369, Hardcover: 320 pages, available from Amazon.com and also. See our of this publication. Decks and Porches, the JLC Guide to, Best Practices for Outdoor Spaces, Steve Bliss (Editor), The Journal of Light Construction, Williston VT, 2010 ISBN 10: 1-928580-42-4, ISBN 13: 978-1-928580-42-3, available from Amazon.com.
has generously given reprint permission to InspectAPedia.com for this article. All rights and contents are ©Journal of Light Construction and may not be reproduced in any form. Architectural elements: the technological revolution: Galvanized iron roof plates and corrugated sheets; cast iron facades, columns, door and window caps.
(American historical catalog collection), Diana S Waite, available used out of Amazon. Asphalt Roofing Residential Manual from ARMA the Asphalt Roofing Manufacturers Association Website,. Building Pathology, Deterioration, Diagnostics, and Intervention, Samuel Y. Harris, P.E., AIA, Esq., ISBN 0-471-33172-4, John Wiley & Sons, 2001 General building science-DF ISBN-10: ISBN-13: 9728. Building Pathology: Principles and Practice, David Watt, Wiley-Blackwell; 2 edition (March 7, 2008)ISBN-10: ISBN-13: 9039.
Built-Up Roof Systems, Manual C.W. Griffin, Mcgraw-Hill (Tx); 2nd edition (July 1982), ISBN-10:, ISBN-13: 9833. Concrete Folded Plate Roofs, C. Wilby PhD BSc CEng FICE FIStructE (Author), Butterworth-Heinemann, 1998, ISBN-10:, ISBN-13: 9663.
Concrete Shell Roofs, C. Wilby PhD BSc CEng FICE FIStructE (Author),. Concrete Dome Roofs (Longman Concrete Design and Construction Series),. Concrete Roofing Tile, History of the, Batsford, 1959, AISN B000HLLOUC (availble used).
Copper Roofing, by CDA. Copper Roofing, Master specifications for copper roofing and sheet metal work in building construction: Institutional, commercial, industrial, I.E. Anderson, 1961 (hard to find). Corrugated Iron, Building on the Frontier, Simon Holloway. Green Roof Plants: A Resource and Planting Guide, Edmund C. Snodgrass, Lucie L.
Snodgrass, Timber Press, Incorporated, 2006, ISBN-10:, ISBN-13: 9870. 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email:.
The firm provides professionaland also extensive and home inspection-related. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home.
Many opal cutters will sell stones that have cracks or crazing in their opals. There is a major difference between the two and we will show you what it is. While there is nothing wrong with buying an Opal that is crazed or cracked it is important that the buyer is made aware before the purchase. If your Opal does have fracture lines in it or it has crazed do not put it in an ultrasonic cleaner as it may destroy the Opal. CRACKSA crack can be a minor or major fault line. It can be on the surface or internal.
If you see a line inside the opal and it reflects light then it is a crack in the stone. External cracks will decrease the value / price more than internal cracks.Internal cracks have been shown to be stable and not continue to grow. Some Opal miners have stones with cracks inside them that have had no movement. External crack lines in a polished opal can be cut out but obviously this decreases the size and value of the Opal.Cracked opals do not necessarily mean that they will fall apart. Many cracked opals will hold but the biggest problem is if an opal is cracked and in a ring, the everyday wear and tear and knocks will break the Opal.
Many cracked opals are set as pendants for this reason and are able to be worn most of the time. CRAZINGCrazing looks like multiple crack lines. Crazed opal is mostly kept as specimens or collectors pieces. They are not recommended for use in Jewelry. Crazed opals can be treated with Opticon which stabilises the Opal.The image above is an Ethopian Opal with an inclusion.
Notice there is no light reflection.Inclusions are not cracks. Many opals contain natural inclusions. These can be air bubbles, vegetation matter and even potch. AUSTRALIAN OPALMost Australian opal is very stable with black opal N1 considered the most stable due to its smaller molecules.
Generally Australian Opal that displays a crack is set at 10-20% of the value of a stable opal of similar qualities. It is estimated only around 1-3% of Australian opals crack but some opal fields are more susceptible than others.Most Australian Opals contain 3-5% water. Generally the deeper the miner digs the more water content the Opal will have. Mines at Lighting Ridge go down to about 30 meters and the miner can gauge how stable the Opal is. As the potch goes from tough dry material to soggy wet potch then it is an indication of stable material.
When they go deeper and the miner knows that this opal will obviously have more water content.Most Australian opals are non porous and therefore they do not absorb water. POTCH LINESSome opals may show veins or spider web lines. These are not cracks but potch lines. It is easy for the cutter to check as crack lines reflect light but potch lines do not.
Potch lines do decrease the value of the opal depending on the severity of lines. They do not generally effect the stability of the opal. ETHIOPIAN OPAL.
Hydrophane opal absorbs water. When is dehydrated the base is more opaque. When the opal is hydrated it becomes more transparent. Transition time from hydrated to dehydrated can vary from minutes to days but most Opals do transition in a few hours. FRACTURE TESTING ETHIOPIAN OPALGemstones have been fractured or cleavage tested for centuries to test parting or cleavage in rough material. All major carving or cutting centres fracture test material before cutting or carving.Even before modern testing techniques were invented rough material was still tested. During winter a wood fire would warm up a room and cold water was splashed repeatedly on the rough.Today this basic process is still used for opals by soaking the opals in water and drying them in a warm but not hot environment.
This processes can be repeated several times before the cutting process starts. Some opal with a small crack line will sometimes expand under water.This process tests the stress points and cracks will appear on the weakest cleavage point. The opal is now ready for cutting and polishing to remove any visible cracks.Fractures or crazing and cracks can appear as:. granular sugary patterns. smooth even breaks. rough edged irregular breaksCutters obviously make decision to cut an opal after it has been fractured tested as to observe which side of the opal the fracture occurs on. This involves great skill and a professional cutter will cut according to the directions that have opened up when the fracture is complete.It takes a cutter many years of experience to understand the best approach to cutting an opal.
Master opal cutters will charge a percentage cutting fee for top stones from 3 to 5% and in most cases this is worth paying! OPTICON STABILIZATION. Opticon is the most common form for stabilising opal. Immerse the stones in a canning style jar filled with enough Opticon to cover the stones and tighten the lid so water can not escape. Condensation can turn the resin cloudy.
Place the jar in a ordinary slow cooker filled with enough water so the jar dose not float. Turn the heat up to 150-170 degrees Celsius (302 - 338 Fahrenheit).
use a thermometer to check the temperature. We recommend using a kitchen meat thermometer.
Cook for 24 hours. Strain off the excess resin and place on tinfoilUse a vacuum machine like the ones used to vacuum food bags. This sucks the air out of the bag.
Vacuum for at least one hour. Using an artist style brush paint the stone with a weak mixture 40 to 1 of resin and hardener and re vacuum for 15 minutes. Remove any excess moisture with a acetone cloth. When the stones are no longer tacky polish or re-polishThis 54.7 carat Harlequin pattern opal was sold for over $1,100.
When it was cut 5 years ago it displayed crazed lines. The owner treated the stone with Opticon and sold it for around 10% of its value if it was untreated. You can also coat the stone with super glue and heat it under strong lights. The glass like covering over the stone gives it stability while it is polished. BOULDER OPALBoulder opal is mostly formed on an ironstone backing and is stable. This ironstone can be A deep brown chocolate color to sandy ironstone with a light brown colour.
Ironstone does help to keep the opal stable. Some crack lines may appear at a 45% degree angel but the opal can still be stable.
Some boulder crystal opal may also display cracks. Koroit and Yowah opal fields are considered stable.MEXICAN OPALMost Mexican opal is stable.
Crazed or cracked opals can occur when the potch and opal cut in one piece as each has different pressure threshold.U.S.A. OPALSUSA Opals are generally not considered to be stable and opals are mostly made in to Triplets or stabilised. USA opals tend to craze as water content can go up to 14% BRAZILIAN OPALSThese are generally considered stable as the water content is mostly less than 5%. The opals are semi translucent to white translucent. HONDURAN OPALHonduras opal on matrix is considered stable but some crystal formed on matrix may display crack linesBrowse Our Opals.
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