Water Intrusion

Water, Water, Everywhere

Typically when I am discussing water problems with the condo’s property manager or the board, the focus is on leaking roofs, foundations, windows, or other building envelope points of water infiltration.  Instead, this article’s focus will be on water damage problems from inside sources and their prevention.

It is hard to talk about inside water damage without also considering a lengthy discussion of insurance matters, but I’ll try.  The short answer is both the board and the unit owner should confirm the correct policies are in place.  The association’s master insurance policy review should determine if the policy covers both as-built and upgrades (i.e. betterments and improvement clause) or just the walls, floors, and ceiling.  The unit owners should consider sewer/ drain back-up coverage, if the policy does not.  Keep in mind, insurance adjusters are looking for ways to avoid claim payouts.  They will look for the source of the water and whether it was caused by accidental reasons or old age wear and tear; lack of maintenance; or your negligence.

So why is internal water damage such a big deal?  It is because it is the number ONE insurance claim in the nation beating out other high profile claims including tornadoes, hurricanes, and wildfires.  And it is growing.  1 in 50 homes experienced an internal water claim in the five year period of 2013 to 2017 per Verish Analytics ISO who provides insurance industry statistical data.  This 5-year claim rate of 2.05% per dwelling is up from the prior 5-year statistical period rate of 1.44%.  This equates to an average $10,000 per claim and $13 billion in total claims for 2017.  It’s a big deal.

So why is this happening?  The short answer is the trends in condo and HOA development and the aging of residential building inventory across the country.  The burst in condo development in the 1980’s and 2000’s have resulted in many more water sourced appliances in risky locations.  Many homes built in the last 20 to 30 years have laundries on the second floor instead of the more traditional basement location where a leaking hose could be dealt with a mop and bucket.

Some homes can have more than 40 water connections including washing machines; water sourced heat pumps; ice makers; wet bars; filtration systems; extra bathrooms; dishwashers; garbage disposals; indirect hydronic floor heat; and the list goes on.  This partially explains why fire damage claims in the US have declined while water claims have increased, not only in numbers but in amount.  High-end properties are the worst for this increase in water claims.  For homes valued greater than $500,000 the claim sizes have doubled since 2015 while homes valued greater than $1 million have tripled in size according to the Wall Street Journal.

So what’s a property manager, board, or unit owner to do?  Protect the home.  Needless to say, each condo or HOA complex has its own factors of importance.  These factors must be considered and a plan should be established to minimize the potential problems each type of complex should address.  One place to start is the creation of a central maintenance log to record all reported internal water events to determine if there is a trend or pattern.  An aging condo may have experienced a rash of washing machine hose leaks.  This may prompt the property manage to notify unit owners to inspect their own hoses for wear or even hire a plumber to inspect all of the units’ water sourced appliances.  Another HOA may have a population of ‘snow birds’ who should be cautioned to maintain their unit thermostats at a certain level to avoid pipe freeze up while they are vacationing in warmer climates.  Sometimes a global reminder to all unit owners of the location of their central water shut off valve for future water emergencies is a good ounce of prevention.

Needless to say, no matter how much a property manager or board thinks about internal water damage, it often comes down to the individual unit owner being responsible to maintain the unit.  Investing in water sensors at some risky or perennial problem locations may be money well spent.  Educating the unit owners through the association’s newsletter or web site is also a step in the right direction.  Reminders of the importance of maintaining caulk in the tubs and showers; hose connections for all appliances; and periodic observations around the home looking for developing rust; drywall damage; and pooling water can go a long way in preventing a trickle becoming a sea of trouble.


Article written by Jack Carr, P.E., R.S., LEED-AP, Criterium Engineers

Published in Condo Media May 2019 edition

Download a PDF copy of this Condo Media Article

Read more

Basement Waterproofing – How do you keep water out of a basement?

Maintain proper drainage

Basement Waterproofing - How Do You Keep Water Out of a Basement

A cost effective approach to basement waterproofing is to maintain with perimeter surface drainage conditions.  The importance of proper drainage and landscaping (mature trees) around a foundation cannot be over emphasized.  Poor drainage around the foundation is the most common cause of foundation problems and basement moisture problems.  Drainage and moisture control around the home include proper ground slopes away from the foundation.  It also includes keeping your gutters clean and the downspouts functional.  Not doing so, allows the water from the roof to overflow the gutters.  This water then runs along the foundation and in turn can cause basement seepage or foundation movement.

New Construction Basement Waterproofing

In new construction, cast-in-place concrete foundations are more resistant to water penetration than concrete block. Bituminous waterproofing should be used, at a minimum, to seal the outside of any foundation wall, however. An effective perimeter drain system should be installed to collect water from around the foundation and under the slab.

The National Association of Home Builder’s booklet on dry basements entitled, “Basement Water Leakage – Causes, Prevention, and Correction,” recommends perimeter drains on the inside and outside of the foundation. These drains should either flow downward to a gravity outlet (natural drainage) or to a sump where the water can be discharged with a sump pump.

A building built in a wet site should take advantage of additional waterproofing; a membrane system. One example of a membrane system consists of multiple layers of impervious material applied in a hot tar mopped system to the outside of the foundation. Special attention should be paid to the joint between the wall and the footing. The concrete floor and walls (whether block or concrete) should be reinforced to minimize cracking.

Existing Construction Basement Waterproofing

A water problem in an existing basement can only effectively be dealt with by:

  • rewaterproofing the outside of the foundation walls and/or
  • upgrading the exterior foundation drainage system

Both approaches require excavation around the outside of the foundation.

There are alternatives which will intercept the water using a channel-like system around the interior of the foundation wall to collect and guide the water into a sump and discharge it using a sump pump. These systems do not correct the water problem but they do control the water once it has entered the basement in a way that minimizes problems related to water entry. Such systems, while dealing more with the symptom than the cause, are typically less expensive because they can be accomplished from the inside.

Ultimately, when dealing with a basement water problem, the tried and true conventional methods working from the outside are still the most reliable.

Basement waterproofing and existing building, or rewaterproofing, the outside of a basement wall requires excavation to the full depth of the wall, careful cleaning of the wall surface and proper application of bituminous waterproofing. A multi-layered membrane system should be used if the surrounding water conditions are severe. At the same time, a perimeter drain system should be installed, similar to the recommendations noted above for a new foundation. If there are cracks in a wall, the cracks should be chipped out to form a V-groove along the length of the crack approximately one inch deep. The V-groove should then be sealed with a good quality epoxy or silicone caulking, filled with mortar and covered with bituminous waterproofing.

Epoxy injection

An effective, but sometimes expensive alternative, is epoxy injection into the crack. This can be done from the inside. The epoxy bonds with the concrete and creates a somewhat permanent seal against water penetration. The limitations to this system are cost and effectiveness, depending on the size of the crack. The smaller the crack, the less likely it is that full penetration injection is possible. However, before undertaking expensive excavation around the outside of a foundation, you may want to get proposals from local epoxy companies to compare the cost and potential effectiveness.

Basement water is controllable but there is no easy answer. Only the more complex and sometimes expensive approaches are truly reliable.

Peaceful Coexistence

Peaceful coexistence is sometimes an appropriate resolution to a basement water problem. While keeping water out of a basement may seem ideal, there are risks. Preventing water from entering an older stone or concrete block foundation can cause water to accumulate on the outside of the foundation walls increasing water pressure on the walls themselves. The result can and has been total failure of the foundation wall. Where the construction of the foundation wall is marginal or questionable, the better approach to water control is to permit the water to enter, collect it into an interior drainage system, guide it to a sump and pump it away.

Check out our Residential Services to learn more about how we can help!

Read more

Water Intrusion

“Water, water everywhere” is not what you want to be thinking as you’re staring through the windows of the restaurant, drug store and appliance shop that are tenants in the building you own.  Water inside a building means likely damage to the furnishings and fixtures, floors and walls inside; it also means the possibility of rotting wood and mold risks; and it means major liability risks.

“Water intrusion,” which is how engineers define the problem, can have many causes, but the most common is construction flaws in a building’s envelope – the vertical surfaces running between the foundation and the roof that separate the interior from the exterior.

The envelope should be water-tight, for obvious reasons; unfortunately, we find that is not the case in many of the commercial buildings we analyze.  For purposes of this discussion, we are not talking about “trophy buildings” – the towering skyscrapers that define an urban landscape.  We’re talking about the small strip malls with a handful of stores that are ubiquitous in the suburbs.  The buildings are low-rise – typically only one-story—and they are usually managed by their owners or by small property management companies, which may in itself increase their vulnerability to water intrusion problems.

Compared with a corporate owner or a management company overseeing multiple large-scale properties, individuals who own and manage small strip malls are likely to be excessively cost-conscious (which sometimes means “penny-wise and pound-foolish”), and inclined to push building components, like the roof, to the end of their life expectancy, patching rather than replacing them when problems appear.

An older roof, oft-repaired, is more likely to leak than a newer one (that is well installed, not all are) or one that has been consistently well-maintained.  Leaks in a well-maintained roof will usually be relatively small and isolated; leaks in a neglected roof are likely to be larger, more widespread, and more damaging as a result.

The flat roofs common in commercial buildings are also more prone to leaks than slanted ones. And small commercial properties are particularly vulnerable to roof damage caused by third parties.  Commercial tenants are usually responsible for building out their spaces.  A mall with eight spaces could have eight different tenants with eight different contractors, all dispatching different workers to install or connect equipment on the roof. The more people traipsing around a roof, the more opportunities for someone to drop a tool, dig a heel, fail to seal an opening, or otherwise damage or weaken the surface in ways that aren’t likely to be discovered until the roof starts to leak.

When we are looking for the source of water intrusion, a damaged or neglected roof is always a prime suspect, but by no means the only one. Architectural features also rank high on the suspect list. Consider the glass storefronts and glass curtain walls that are standard in strip malls.  Poorly installed windows are a leading source of water intrusion in residential buildings.  The problem is magnified in malls, because they have a lot more glass that requires a lot more maintenance to keep the installations water-tight.

Malls don’t have balconies – another intrusion point in residential structures.  But they do have loading docks that are not always treated tenderly by the truck drivers who back into them.  Cracks in the docks can funnel water into the building.

The building’s siding can also be problematic.  Experts will debate endlessly the relative advantages of different siding products, and there is no question that some are better than
others.   But if water is seeping into the building, we find it is most often the quality of the installation, not the quality of the product that is at fault.

For example, Exterior Installation Finish Systems (EIFS) are now widely used in commercial structures.  Comprised of a synthetic material that resembles stucco, the finish looks smart and works well – if installed properly.  But if the insulation is inadequate or if transitions aren’t sealed properly, the surface won’t be water-tight.

One of the most common installation mistakes is the incorrect layering of building envelope materials. When this occurs, instead of being shed efficiently from one material to another, water accumulates behind the materials and penetrates the structure.

Design features intended to increase the visual appeal of a building can also increase its water intrusion risks.  Varying the materials, using different shapes and inserting angles all add architectural interest.  But if the different materials used are incompatible, the resulting temperature variations can cause sealants to fail.  And every angle you create, every transition you make from one shape or material to another, creates a point at which water may intrude.  Transition or termination points represent a tiny portion of a building’s envelope, but they account for much of its vulnerability, and they don’t always receive the water-proofing attention they need.

There are no perfect buildings.  Water intrusion is a potential risk for all.  But owners of commercial buildings can reduce their risks by being mindful, diligent and proactive. Here are a few suggestions:

  • Don’t ignore early signs of water intrusion.  If you see water stains on ceilings or walls, don’t ignore them. The sooner you identify the source of water intrusion problems, the more controllable they will be.
  • Bring in experts to investigate.  They can provide the objective analysis you need and they can be held accountable for their findings.   Often, properly performed water tests are necessary to definitively diagnose water intrusion.
  • Take care of preventive maintenance.  This includes more than painting or power washing the exterior.  Replace (and, if necessary, upgrade) the sealants around the perimeter of windows and curtain walls.  This is your best defense against water intrusion in those areas.  Good sealants last a long time, but they don’t last forever.   Experts suggest re-sealing every 5 years on average – less frequently in some parts of the country, more frequently in others, depending on the climate.  Preventive maintenance should also include an annual roof inspection performed by an expert.   Make necessary repairs when they are indicated and make sensible decisions about when it is most cost-effective to replace the roof rather than to continue patching it.
  • Consider flooding risks.  Although most water penetration risks are centered on the building envelope, ground level flooding may also be a concern for small commercial properties, because they are often built on less than optimal flat sites with less than optimal drainage systems.  A heavy rain that floods the parking lot could flood the building as well.  A civil engineer can help you asses the flood risks for your property and recommend any mitigation measures you should implement.
  • Don’t look for short-cuts.  There are no Band-Aids for water intrusion.  If transitions on the building’s surface weren’t set properly, you have to re-do them. If the siding wasn’t installed properly, you may have to replace it.  If the roof is failing, you‘ll have to replace it, too.  These measures are going to be expensive. But preventing water intrusion will be far less costly than repairing the damage it can do to your buildings, to the property and health of your tenants, and to your finances.

The Engineering Advisor is intended to enhance your knowledge of technical issues relating to buildings.  For additional information on any subject, please feel free to call us.  Our commitment is to provide you with timely, accurate information.

Read more