Read the Fine Print

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Many of the large insurance companies can make it very difficult for home and building owners to receive the maximum insurance funds in a catastrophe. Additionally, they will constantly move the goal post, re-writing their policy language. After you file a claim, insurance companies send out their inspection adjusters and you are notified of your final claim dollars. Often times building owners are in a situation where they need to negotiate with insurance companies and show evidence to get their full coverage on severely damaged exterior building products. I know this first hand.

Over the decades, after overseeing the completion of more than 50,000 roofs, I have seen insurance companies continually change claim coverage on crucial exterior building components. About 15 years ago my own home was hit by a horrific hail storm leaving nearly two inches of shingle granules in my gutters. Shingle granules are vital in preserving the lifetime of the roof by protecting the underlying asphalt from the sun’s harmful UV rays. This impact to my new 40 year shingles cut their life in half. I assumed my insurance company would cover such loss but they had discontinued granular loss coverage for some reason from hail damage. The news was quite a blow knowing that without granules the shingles will not last…period.

Through 40 years of field and personal experience dealing with hail and insurance companies, I have compiled a team to bridge the gap between building owners and the insurance companies. As a local engineering consulting firm it is our goal to help you in these situations and be your consumer advocate!

Storm damage is covered on your policy. It is my fear that all damaged pertinent materials should be replaced in order to protect your home long term and many times it’s not. Contact us, we want to make sure your home performs and is sheltered from the storm AND fine print.

Heaving Concrete and Asphalt – Subgrade

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In Minnesota, there are some excellent references that can be used as a guide for the design and construction of residential driveways. However, what is needed is a code that addresses the key elements of a driveway structure. I find it fascinating that there is nothing in the code that addresses the design or the construction of a residential driveway.

In my professional opinion, the key elements to a properly designed residential driveway are as follows: the proper subgrade with the required compaction, a solid base upon which the driveway material will rest (this blog is based on an asphalt driveway), the right asphalt thickness, and once the driveway is constructed, preventing water from entering the subgrade (water management system).

Proper Subgrade

What is a proper subgrade? The answer – one that is NOT prone to frost heaving.  Damage from frost heaving can result in the buckling of garage door trim which can cause the misalignment of your garage door. This misalignment can make it difficult to open and close the door.

Buckling of garage door tripm. Clay soils push concrete soils upward in winter.

Buckling of garage door apron. Clay soils pushes concrete soils upward in winter.

The subgrade should either be granular or con-bit.  Most subgrades today consist of clays and silts, soils that are considered expansive – these materials are not the proper subgrade.  If you have subgrade consisting of clays and silts, it should be removed and replaced with granular material or con–bit (this is normally referred to as a soil correction). Here at CBS we recommend using con-bit rather than granular material. Whether it is con-bit or granular it must be compacted and it should be compacted in lifts. Each lift should be about 8-10 inches. Once the subgrade is prepared then the base is constructed.

Concrete and asphalt can move as much as 8 inches when the soil beneath it freezes.

Concrete and asphalt can move as much as 8 inches when the soil beneath it freezes.

Many driveway problems occur right in front of the garage door. This is an area where the native soils are used for backfilling and they are seldom compacted properly and are often placed wet. This area is prone to becoming “wetter” over time because other elements feed moisture into it (poor water management systems). Disregarding this compaction and allowing the subgrade to become saturated are the key reasons why driveways settle and are subjected to frost heaving.

 

Moisture Intrusion Solutions: Solid Base & Asphalt Thickness

The next element of importance in a pavement structure is the base. The base is the layer directly below the driveway surface (either asphalt or concrete). AS previously stated, this article is based on a hot mixed asphalt driveway. The base material, in my opinion should be a class V material or con-bit (recycled concrete and asphalt). The thickness of the base will depend upon the thickness of the asphalt.

Let me explain – the design of the pavement structure should be based upon a term called “Granular Equivalent” (GE). The granular equivalent concept defines a pavement section by equating the thickness of the base and asphalt layer to an equivalent thickness of granular base material. Note: this is not my term, but a term used by the Minnesota Department of Transportation (MN/DOT) for designing pavement sections.

As an example, a class 5 aggregate base has a granular equivalent of 1 per inch of thickness and an asphalt course has a granular equivalent of 2.25 per inch of material.  So, if I have an asphalt thickness of 3 inches, and a class 5 course of five inches, my granular equivalent would be 11.75 inches. If I had an asphalt thickness of 2 inches and a class 5 base of seven inches, my granular equivalent would be 11.50 inches.

So, you see the granular equivalent can be any combination of asphalt and base. It goes without saying that the higher the GE number, the better the pavement structure (I have personally seen this to be true).  Low GE’s might not show pavement distress in the first few years but within 3-7 years, signs of distress will begin showing up.

The next element in the pavement structure and the ones everyone sees, is the surface course. To be frank, I am not sure what specification most residential paving contractors use for their design mix. I have seen HMA thicknesses from 2” up to 3” used for driveways. I think most paving contractors will use 2”-2 ½”. Especially in large residential developments. If you are an individual homeowner the contractor will probably use 2 ½” – 3”. In my professional opinion, I would recommend 3” – 4”.

Now getting back to the GE. I would recommend a GE between 10.5”-12” for residential driveways. Similarly, for reference – the Minnesota Asphalt Pavement Association (MAPA) recommends a GE of 11.5” for driveways also.

Conclusion:

The building codes govern the applications of these materials and practices. Neither the IBC, nor the IRC include information for residential driveway designs. Nor is there a recognized national standard. Maybe it is far “fetched” of me to think that one could be established, but at the very least, I believe the Minnesota State Building Code should address the issue.

Incidentally, I have over 30 years of experience with the Hennepin County Department of Transportation dealing with bridge and roadway designs.

 

 

 

Boulder Retaining Wall and Related Drainage Issues

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Boulder retaining wall

The above picture demonstrates how a boulder retaining wall has moved along side the foundation of a home since its initial construction.  Boulder retaining walls are a common landscaping and erosion control method used in many homes.  If a foundation wall is over 48 inches, it needs to be designed by an engineer and requires plans for ordinance and structural review by the local governing body.

There are many elements that can encourage boulder wall movement, but here are

the three main causes:

1.) Often, the wall has been built on unsuitable soils that lacked compaction and ultimately could not support the weight of the wall. Contributing further to this problem, is the added pressure from the soil and related area behind the wall.

2.) Secondly, sometimes retaining walls are built with improper drainage behind it, including no installation of drain tile, drainage material behind the rocks and/or fabric to hold that material in place.

3.) Thirdly, the poor drainage of rain water behind the wall causes erosion to take place and further soil settlement under the boulder wall itself.  This water often comes from a roof or rain gutter that empties behind the wall.

In this case, as the picture depicts, some of those elements were present. This wall had movement subsequent to its initial construction.  This resulted in damage to the outside parge coat on the foundation wall of the home and a leak developed in the basement adjacent to this boulder wall.

Here are some of the things to consider when constructing a boulder retaining wall:

  1. How high is the rock wall going to be? Will it need to be engineered?
  2. Location of the rock wall, asking is it on stable slopes, consisting of firm, undisturbed soil?
  3. The ground surface above the Boulder Wall. How much water will come through this area?
  4. The proper angle of the rockery face of the Boulder Retaining Wall.
  5. The proper rock size should be used to construct the wall.
  6. Rock placement including the rocks to be embedded into the soil at the base to provide maximum stability.
  7. The drainage must be provided behind the wall to assure that water will not erode the soil behind or underneath he boulders. This includes the use of a drain tile system, erosion fabric, and drainage material such as gravel behind the boulder wall itself.

As a homeowner, before taking on construction of a boulder wall, you may want to check with experts in this area.

 

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High Energy Bills: The Truth about the Attic

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Ice Damming Prevention MN

What if we told you there is a way to drastically decrease your energy loss and ultimately put money back in your pocket?  All you have to do is, look up. Your attic could be needing some serious attention.

It is common knowledge that warm air rises towards the top part of a building. This creates a pressure gradient within the structure. A higher pressure exists near the uppermost part of a building while a lower pressure resides near the bottom. Ultimately, the low pressure near the foundation will pull cool air into the building while the high pressure at the uppermost part of the building drives warm air out through any crevice it can find.

 No wonder your energy bill is literally THROUGH THE ROOF!

You can see why it is so important to have a properly insulated attic. In order for an attic to perform at its best, it must function as a system. Three main areas must work together to ensure peak performance:

  1. Bypasses

Frequently, the ceiling bypasses are not sealed correctly rendering the attic insulation ineffective. Sealing bypasses can be anything from an interior wall extending into the attic, ducting, bathroom fans, plumb vents, lights, and wires. Many times, these bypasses are not insulated at all, leaving the home vulnerable to serious energy loss.

  1. Insulation

Insulation is naturally resistant to conductive heat flow. Depending on the density, thickness, and type of insulation, the level of resistance, or R-value, varies.  A higher R-value will be more effective against heat trying to escape. Your geographic location helps to determine how much insulation you need. Again, the more insulation used, the higher the R-value.

  1. Ventilation

An effective ventilation system helps keep your attic at a temperature which allows for best performance. Keeping attic temperatures down in the summer while also keeping the attics dry in the winter is essential. This allows for a prolonged life of materials and structures as well as lower energy bills

All three of the systems mentioned above must work together in order for a home to function at its best. Having a new home does NOT guarantee this.

Luckily, CBS has ensured peak attic performance in more than 120 townhome association’s in order to eradicate heat loss due to incorrectly insulated ceiling bypasses. Our experienced engineers understand that insulating an attic is irrelevant if the bypasses have not been sealed properly. Our team addresses the attic as a whole structure, not just as individual parts, in order to find the root of the problem and act accordingly.

Be aware! If you have/are experiencing any of the following, your attic may need some attention:

A) Ice dams

Ice dams

  • When heat escapes through poorly insulated areas, the attic is warmed up and melts snow on your roof. This melting snow migrates to the edge of the roof where it freezes and continues to build up and hold water in the form of a dam. This is a serious issue that can lead to further problems such as severe water damage.

For more information on ice dams, check out a previous blog: Ice Dams vs. Natural Ice Build-up

B) Mold

  • As we touched upon earlier, warm air rises and will try to escape out of any open channel it can find in your attic. An open bypass is a great vessel for this air to escape. As the escaping warm air meets the cool air from outside, condensation is formed. This condensation, along with other forms of moisture intrusion, leave your home very susceptible to mold. This mold will be apparent not only within the attic, but on walls and other areas of the home. Think of the health implications this proposes.

C) Nail pops on roof

  • The hygroscopic nature of plywood or OSB (oriented strand board) contributes greatly to the nail pop issue. Plywood is made from several layers of veneer held tonail popgether by glue. During periods of drastic temperature differences (40-50 degrees F difference) between the attic and exterior, expansion and contraction between the different layers of veneer (or within OSB) occurs. What do you think happens to the wood when this takes place? Here’s a hint, we have all experienced this at one point or another. Yes, the wood literally becomes unglued! You can see why this is a problem. The nails are slowly and forcefully pushed upwards due to the conflicting movement (“ungluing”) of the wood. This phenomena transpires more frequently as moisture content in the attic increases, primarily from unsealed bypasses.

Nail pops must be taken care of immediately in order to prevent moisture intrusion, however, if your attic is not insulated properly, they will continue to occur. If you are interested in prolonging the life of your roof, this issue must be acknowledged and corrected.

D) High energy bills

  • Your energy bills could be high because your attic is not sealed and insulated properly. Remember, heat rises and will escape out of any area it can find. If measures are not taken to keep heat within the home, such as sealing bypasses, your hard earned money is being lost to the atmosphere.

Want to learn more about energy savings? Check out this blog: Energy Savings

If you have noticed any of the above issues, it is time to call CBS. Using our expert knowledge to best assess your needs, the root of the issue will be determined and corrected.  Don’t waste time and money addressing symptoms that come from a poorly insulated attic when the real problems are still lurking within. Imagine the peace of mind and money saved by having a smaller energy bill, the lifetime of your roof extended by 15 years, prevention of water damage, and a healthy family. Why not call CBS to take care of the real problem once and for all?

Contact CBS

 

 

 

Patio Door Malfunctions

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This time of year we tend to receive a lot of calls from homeowner associations regarding operational issues and failures related to patio door assemblies.  These include inoperable doors, locking devices not joining properly, weather stripping issues, cracked drywall finishes around door assemblies, etc.

In January, I spent a great deal of time with a 100 unit association on the east side of the Twin Cities and a 40 unit association on the south side.  CBS was called out to investigate failures in both sliding and French patio doors, finding that the bulk of them were inoperable.  While we found the doors themselves to have little to do with the problems, unit owners were less than thrilled because they bought into homes that contained quality name brand doors.

In the case of the 100 unit association on the east side of the Twin Cities, the patio doors were skirted by a concrete slab belonging to individual patios on the outside of the structure.  During the original build, the grade on the concrete slabs was improperly set and did not shed water away from the doors.  Instead, the grade actually invited water back under the doors.  On a molecular level, concrete has porous properties and because of that will absorb some amount of moisture.  During the winter months the concrete will freeze and thaw with the seasonal changes and the concrete and exterior building components that are now saturated will take on a new demeanor.  As the water turns into a solid state, the concrete slabs as well as framing members beneath the door begin to expand.  This expansion in materials causes the door itself to rise up.  Many of the doors cannot handle the increased expansion from the water turning to ice.  Sometimes the door itself will change enough to where the locking mechanism will not work, and often times the sheetrock finishes inside the home will crack above the door assembly as the entire frame moves up.  The natural warming of the spring weather turns the ice back into water and then allows the door to settle back into its original location.  Not only is this entire seasonal process a nuisance but the integrity of the building materials around the door are being jeopardized.

This situation can be corrected in one of two ways: the annual arrival of spring or by lasting, engineered solutions from CBS.

In the case of the 40 unit association on the south side of the Twin Cities, there are no elevated patios or decks.  Instead, there are walkout ground level concrete patios beneath the doors.  The failure in patio doors at this complex comes under the guise of unsuitable soils beneath the patio slabs with the absence of water management leading to the patio doors.  Many of the issues and damages are similar to the ones described above.  Water turning to ice in this case stems beneath ground level with water being invited back to the foundation by faulty soils at the concrete patios.  Expansion of the soils during the colder months pushes the concrete slab up against the door sill thus raising the entire frame of the door assembly.  The door frame and surrounding framing is no match for Mother Nature and the pushing forces that are instilled upon this component of the home.

Again, there are two ways to correct this situation: that annual arrival of spring or by lasting, engineered solutions by CBS.

A previous blog by another member of the CBS Team talks more in depth about negative grade, water management, and its lasting effects on your home.  If anything in this blog is a problem you are experiencing please don’t hesitate to get in touch with us and end your patio door problems once and for all.