Thoughts on the Engineering Industry

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Archive for the tag “Roof”

Four Basic Steps to Determine if your Shingle Roof Has Been Damaged by a Hail Storm

Hello everyone, I hope your weekend went well.  I went to see the new Bond movie with my brother Friday and last night I went to a west coast swing dancing class and social event.  Other than that, I’ve been doing my usual stuff like working out and my job inspecting buildings.  Today, I’ve decided to write a blog post explaining four basic steps to determine whether a composition shingle roof has been damaged by a hail storm and quantify the extent of damages.  I’ve avoided this topic for two reasons: one is that there is a lot of information out there about this already, and the second is that it takes some prior experience to make an accurate assessment.  However, it is one major component of my job and I feel like I can provide some practical information that will help you should you need it.

1) Look for spatter marks on surrounding surfaces (http://goo.gl/COQH3i)

Spatter marks serve as a indicator of the size and direction of the recent hail.  The size of the spatter can be compared to the impact marks elsewhere to determine the extent of recent damage.  The directionality can be determined as well by figuring out which directional faces have or do not have spatter.  In addition, spatter will fade over time – this can differentiate between different ages of spatter marks within a recent time period in most cases.

2) Look for impact marks at susceptible surfaces (http://goo.gl/m15Wmc)

Impact marks can also be observed on some metal and wood surfaces.  Air-conditioning units are a good indicator due to the fact that they have 4 sides and metal/coil fins that are either soft or oxidized.  Spatter can be observed as mentioned before, as well as indentations.  Furthermore, the indentations can be examined to check for soiling, oxidation, or other forms of staining to determine the relative age of the older indentations.

3) Look at the general condition of the roof (http://goo.gl/7p5Yul)

The general condition of the roof will also affect the extent of hail damage.  Examples of other things that damage shingles aside from hail are general weathering, mechanical scrapes, blistered asphalt, and raised nails.  A roof with a worse general condition will be more susceptible to damage and could reduce the compensation should you involve the insurance company, similar in practice to automobile insurance compensation.

4) Look for hail impact marks and examine their condition/quantity (http://goo.gl/2nguV8)

The last step is to look for hail impact marks on the shingles.  Sometimes a relative age can be determined by checking for weathering of the reinforcement or asphalt within the exposed asphalt/shingle reinforcement.  To quantify the extent of damage, you can count the number of recent and/or old hail impact marks, as well as other general conditions if desired, withing a 10′ x 10′ square.  This is referred to as a test square by engineers and inspectors in the roofing business and is helpful information when estimating the cost of various types of repairs.

These 4 steps are the basic process I use to determine the extent of damage to a shingle roof.  Does anyone else have experience in roof inspections?  If so, what would you add to this list as a basic procedure?  For homeowners, have you had to deal with an issue like this before and how was the experience?  If you enjoyed my post, hit the like button, follow my blog for updates and share this post with your friends.  Thanks for reading and have a good week!

Image source

http://goo.gl/1MbnTT

An Innovative Technology for Concrete Roofing in Remote Areas

     Hello everyone! I hope y’all are doing well.  I’m almost done with grad school and looking forward to that.  Other than that, nothing much has happened.  Today, I would like to discuss a recent development in concrete roofing for remote areas.

     Scott Hamel, a faculty member of UAA (University of Alaska Anchorage), has developed a concrete roofing tile that can be used in place of cast in place concrete roofs.   While working with Habitat for Humanity in Port-au-Prince, Haiti, Hamel noticed that the prefered method of roofing is a cast in place concrete slab because it can double as a second floor if needed and was more resistant to the wind and elements.  However, these roofs weren’t adequately designed in regards to seismic issues and this caused a lot of trouble in the Haiti earthquake of 2010.  Additionally, the usual method for constructing these roofs is to carry up the concrete manually to fill the form work for the roof which is highly labor intensive.  These two combined issues lead him to create an innovative new system for creating concrete roofing.  It is concept that was widely used when making clay roofing tiles up until the 1950’s when improved techniques become more common.  He created a “thin shell, latex modified concrete barrel roof unit” – curved concrete roofing tile in which latex from old paint is added to create to increase flexibility.  To build the concrete shell unit, a mold was designed and the modified concrete is poured in to the mold with mesh metal reinforcement located in the center of the cross section.  Testing is being conducted to determine the optimal shape in regards to stresses and construction applications.

     There are several benefits to using this type of roofing system.  The main one is ease of construction in my opinion.  The roof tiles can be made on site on the ground or off site and easily be taken up a ladder to be put together on the roof.  Another benefit is the cost; according the article the tile will cost $2 – $3 per a square foot versus $6 – $10 per a square foot for cast in place concrete.   The other benefit I find very useful that isn’t mentioned in the article is that it is easily repeatable.  Someone with very little experience can build a safe roof and when there is a crisis like a natural disaster a large quantity of these concrete tiles can be built very efficiently on a larger scale as well.

     Do you think this would be a good roofing system for a remote area?  What if any issues do you foresee?  Are there any other applications this could be useful for as well?  Thanks for your time and have a good week!

Source

Kathleen, McCoy, “Hometown U: A Smarter, Stronger Roof Design for Haiti and Beyond”, Hometown U, March 1st, 2014, http://goo.gl/xk4k23

The New “Flying Carpet” Roof For the Courtyard at the Musée de Louvre

Hello everyone.  I hope your holidays have gone well so far if they started. If not, cram as much fun with your family into the next week.  Today I decided to not post a lengthy or detailed article.  I just wanted to share something cool I just read about today. The Musée de Louvre has recently completed construction on a roof over a courtyard area that literally looks like a flying carpet.

The concept of having a design like this is extremely impressive.  Not only that, there was a lot of coordination and change of work late in the process to insure the architect achieved the desired look.  This is the type of project I would love to work on…very challenging and technical with coordination and team work being a necessity.  In fact, it’s so technical I’m not going to even try to explain the details.  The basic design is a steel frame with various pieces of glass that vary in size and thickness so as to withstand the stress placed on the glass.  The glass is curved and tinted so that it literally looks like a flying carpet and is supported by slender pinned end supports placed such that lateral movements are resisted.  All of this required highly technical computer analysis and was very impressive to read about.  I definitely recommend finding the reference below or finding more information about it if you are a structural engineer.  Below are some photos I found that show new roof structure.

http://goo.gl/YYLSGk

http://goo.gl/x1MnlP

What are your thoughts on the roof?  If you were in Paris, would the Louvre be a place you had to visit to see this structure?  Please share if you find this article interesting and subscribe if you want to read more.  Thanks for your time and have a good week off. 🙂

Resources:

Bucci, Pierluigi, “Flying Carpet”, Civil Engineering Magazine, June 2013, pg 49

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