Home Flippers- Do your research BEFORE you buy

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Home Flippers! Have you ever purchased a home only to find out that it had a bad foundation or cracked joists in the basement? Was it a much higher investment than expected? We have been there and seen it all. Complete Building Solutions wants to assist you with your purchasing decision. Call us BEFORE you buy, so we can help save you time and money.

Foundation Urination

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As you can see in the video above, the title is very fitting.

Earlier this week, CBS was called to investigate a property which had sidewalks tipping towards the front door and block failure. Watch what happened when the soil is excavated away from the foundation! Four to five feet of soaked organic clay mixed with an alluvial layer surrounded the foundation wall. This soil had been holding water for over 20 years as clay will never dry out. After time, the ground water will permeate the foundation and has nowhere to go! The building owner had no indication that their foundation was slowly degrading due to the retained water. CBS is known for drying out properties around the state of Minnesota and this property had the same issues we find in buildings on a regular basis.

Unfortunately, builders/developers are not paid to do correct soil conditions on the property when they do the original dig and build. Inadequate soils should be removed and replaced with compactable aggregates that will retain their shape and shed water at the same time. In this case, the clay surrounding the home was holding water instead of shedding it away from the foundation. Concrete sidewalks and driveways are also susceptible to issues because of soil conditions. The holding of water below the concrete freezes and expands during winter months. In the spring the thawing moisture makes the concrete drop back down creating large cracks.

If you suspect that your building is suffering these issues or showing signs of stress or water, give us a call to help your building perform the way it should!

Why not Building Codes for residential driveways?

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Our company, Complete Building Solutions, investigates construction defects – including but not limited to the building envelope, water management issues, soil issues, settlement problems, concrete issues, and driveways. We also can provide engineering services and construction oversight.

As we conduct our investigations we have found that many of the defects observed do not comply with the building codes.  And, as most people know, the building industry is governed by codes. We rely on the International Building Code (IBC), the International Residential Code (IRC), and the Minnesota State Building Code as our references when conducting our investigations as we look for construction defects. They all do a good job of addressing all facets of a building. But, there is nothing in the code that addresses the design or the construction of a residential driveway.

In Minnesota, there are some excellent references that can be used as a guide for the design and construction. However, what is needed is a code that addresses the key elements of a driveway structure. In my opinion the key elements are having the proper subgrade with the required compaction, a solid base upon which the driveway material will rest (incidentally this blog is based on an asphalt driveway), the right asphalt thickness, and once the driveway is constructed keep the water from entering the subgrade (another words – a good water management system).

What is the proper subgrade? The answer – one that is not prone to frost heaving.  Damage from frost heaving can result in buckling your garage door trim to causing the misalignment of your garage door making it difficult to open and close.

Complete Building Inspections In MN

The subgrade should be either granular or should be con-bit.  I can tell you that most subgrades under driveways consist of clays and silts, soils that are considered expansive – those are not the proper subgrade.  So 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.

The area where we see most of the driveway problems is 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 placed wet. It is the area where the contractor has to excavate in order to install the footing and construct the foundation. Typically the excavation extends out from the building’s foundation several feet and extends down to the footing.

That is also the area that is most prone to become wetter over time because other elements feed moisture into it (poor water management for one). Disregarding compaction and allowing the subgrade to become saturated are the key reasons why driveways settle and are subjected to frost heaving.

Moisture Intrusion Solutions

As previously noted, poor water management can affect driveway behavior. Since the presence of water reduces the strength of the pavement structure, it is important to not let water enter it. I can’t tell you how many times I have seen downspouts dump huge amounts of water right next to the driveway.

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 3-7years, 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:

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.

Bruce Polaczyk, P.E.

Home Inspection Services vs. Engineering Services

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Here at CBS, we are often times called in to find deficiencies in the building performance of townhomes, condos, and single family dwellings.  The items including ice dams, heaving concrete, rot behind siding and moisture intrusion, just to name a few.

Today, most real estate transactions are based on contingencies subject to inspection of these dwellings.  Frequently, at Complete Building Solutions we are asked, “Why didn’t my home inspector find these issues?”

As I answer this question for people, I tell them that there is a notable difference between a home inspection and an engineering-consulting service such as CBS.  The bottom line is this: A home inspection service will typically be used to look over a home in its entirety to see if there are any obvious warning signs for buyers and sellers alike, and are typically done so in a noninvasive fashion.  These items include but are not limited to the installation of appliances such as the furnace and water heater to notable issues with the exterior such as the roof.  With this in mind, the home inspector may not find issues that are hidden.

So, when problems such as moisture intrusion, structural issues, ice dams, heaving concrete, etc. occur and manifest themselves, we at CBS as a construction engineering-consulting firm are called to perform a deeper level invasive investigation.  Complete Building Solutions will dismantle certain areas of homes to determine what is causing the issues, finding the root cause. Inversely, home inspectors do not invasively inspect for such issues that are a lot of time hidden from the naked eye. CBS finds the anomalies with an assessment, document and report our findings, and provide engineering based solutions to improve the dwelling’s overall performance.

Now, do not take this blog out of context.  There is a definite need and market for home inspection services and we at CBS have very positive relationships with many of the best in their field within the state of Minnesota.  As a matter of fact, a few weeks ago we had the honor of being invited to speak in front of 35 home inspectors that belong to the MSHI (Minnesota Society of Housing Inspectors) and are all ASHI Certified.  As I talked through all the issues that we find everyday on structures, I was beyond captivated by my audience of inspectors.  I found in the room a great deal of knowledge, attention to detail, and the overall sincere concern they hold in regards to their clients and the evaluations they provide for their homes.  This should come as no surprise however, because at the head of this organization sits Reuben Saltzman, of Structure Tech Home Inspections.  I have worked alongside of Reuben for many years and am thoroughly impressed with his detailed reports. We work hand in hand when Reuben finds issues that go beyond the home inspection realm and into the need for engineering.  He, along with other members of the MSHI, are very accredited individuals within the home inspection industry.

Here at Complete Building Solutions, we strive to make buildings perform the way they were intended to by presenting a realistic route to resolution, including estimates to have the necessary repairs made, so the home buyer knows exactly what the cure is for the home.  Knowledge is money, especially on the biggest investments we usually make in our lives: our homes.  So if you have building performance issues requiring detailed attention, no matter where you are in the home ownership process, please don’t hesitate to give us a call as we would be happy to assist you in any way we can.  For those of you in need of an accredited home inspector to perform that service specifically, please visit the ASHI website at http://www.ashi.org and search under the “Find a Home Inspector” tab.

And, as always, please check out our website at http://www.cbsmn.com  for continuing information on what we do in the home performance and engineering part of the construction industry.

Stay warm out there

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.

Negative Grade

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This week’s blog is on a topic that has been fresh on my mind as of late, that being negative grade around building foundations.

Many people don’t acknowledge that this plays a crucial role in the longevity of your buildings foundation and the way water moves around your property.  Grade can be defined as slope, and you’ll want to ensure that the soils around your home are sloped in a positive fashion so as to direct water away.  All too often when we get to a property experiencing moisture related problems we find that the soils are pitched back towards the buildings foundation, allowing water to flow back in the same direction.

You may be asking yourself what happened to the soils around my home?  Why did they settle?  Soils around a building will settle over time.  When your home was new, the soils were probably placed in a positive fashion by the builder.  However, most builders will not take the time to compact the soils used to backfill your home because that takes time and resources, and let’s face it, time is money.  You may also want to consider the type of soil your builder may have used to backfill your home.  Sure, you may have some black top soil underneath your landscaping but what’s underneath that?  We typically see a lot of natural clay used for backfill purposes during our investigations.  This is likely because it’s essentially free to use for the builder and it’s already located onsite.  The time of year the soil was placed back in against your foundation will also play a crucial role in things.  Had the soil experienced a month of solid rain, or maybe it was frozen in chunks during the winter months?

Like any building product, soils contain certain properties in the way they move and how well they accept moisture.  Clay for example is a very cohesive soil, meaning it can get very hard when dry but will expand and become something you can throw on a potter’s wheel in art class when saturated.  Throw the seasonal freeze and thaw cycles experienced in a year’s time in Minnesota into the mix and you now understand why this becomes so crucial to the longevity of your homes foundation, surrounding driveways/sidewalks, patios, deck footings, etc.  When correcting the grade around your home we often recommend a soil correction before achieving the final, positive grade away from the foundation.  This entails removing the saturated, cohesive, unsuitable soils used by the builder and replacing them with a compactable, more permeable soil such as recycled asphalt and concrete (con-bit), red rock gravel, or equivalent.  Compaction of this soil in layers is a must to ensure your newly achieved positive grade does not settle leaving you in the same boat you may currently be in.

I briefly touched on moisture in the soils in the last paragraph.  One other item to consider as you look at the settled landscaping around your property is whether or not you have rain gutters along the eaves of your roof and where the rain gutter downspouts drain to.  Rain gutters are a must to direct your roof water where you want it to go and this includes the downspouts.  CBS recommends placing extensions on your downspouts that take the rain water away from all landscaping along your foundation, sidewalks/driveways, deck footings, etc.  Did you know a 1” rainfall will produce .6 gallons of water per square foot of roof area??  That’s a lot of rain water allowed to access your building foundation should you not have rain gutters and downspouts directing this away!

I’m going to leave you with a couple of photos of the damages to building foundations we’ve witnessed due to prolonged exposure to water and negative grade.  The first images are of deck joists that are pulling away from the ledger board due to vertical movement in the outer deck post footings.  Not only may this cause costly damage but may also present a safety factor to its users.

deck joists that are pulling away from the ledger board due to vertical movement in the outer deck post footings

deck joists that are pulling away from the ledger board due to vertical movement in the outer deck post footings

deck joists that are pulling away from the ledger board due to vertical movement in the outer deck post footings

deck joists that are pulling away from the ledger board due to vertical movement in the outer deck post footings

The last image is of a deteriorated concrete block foundation that has been exposed to water in the soils for the last 25+ years.  We actually see this quite commonly, believe it or not.  This moisture in the soils, when combined with the movement in the freeze and thaw cycles experienced in Minnesota, has broken down the concrete blocks to mere sand if you will and can be broken just by kicking them with your shoe.  Concrete products are not designed to take on such moisture and movement in the surrounding soils.

deteriorated concrete block foundation that has been exposed to water in the soils for the last 25+ years

deteriorated concrete block foundation that has been exposed to water in the soils for the last 25+ years

Hopefully after viewing this blog you have taken away something about the importance of having a proper grade around your building that you may want to apply to your own projects this coming spring.  Until next time, stay warm and keep an eye on your buildings!