“I Want to Cover My Concrete Balcony.”

Your attempt to cover the surface of your concrete balcony may be causing more harm than good. Exposed concrete balconies are not always the most attractive, however, certain types of balcony coverings can contribute to premature deterioration of the concrete and reinforcing steel.

Concrete deterioration is the result of corrosion of the reinforcing steel, which creates internal pressures within the concrete causing spalling. Coverings, such as glued indoor/outdoor carpeting, cracked or deteriorated tiles, and inappropriate concrete paints can trap water against the concrete surface. This prolonged exposure to moisture causes scaling of the concrete reducing the concrete cover of the reinforcing steel. The reduced cover will allow moisture to reach and corrode the reinforcing steel.

Figure 1: Surface Scaling  Figure 2: Surface Spalling 

 

We do not recommend the use of glued or loose laid carpets as they typically stay wet for an extended period of time, trapping moisture against the balcony slab surface, increasing the chance of surface scaling.

Now that we have identified the problem, what makes for an appropriate concrete balcony covering?

Selecting a Covering

The three main considerations to keep in mind when selecting a balcony covering are:

  1. Does the covering form a waterproof barrier preventing moisture from reaching the concrete?
  1. Does the covering promote free drainage beneath allowing water to drain from the surface of the balcony?
  1. Can the covering be easily removed during the winter?
  1. Is the covering breathable, allowing drying of the balcony surface?

Let’s examine some appropriate coverings.

Traffic Bearing Membranes

Traffic bearing membranes are coatings which are specifically designed to be applied on horizontal concrete surfaces such as balcony slabs. These membranes form a waterproofing coating that prevents moisture from penetrating the surface of concrete. They’re abrasive and require touch ups every 15 years, but do an excellent job protecting the slab.

Permanent Tiles

It’s important to know that not all types of tiles are appropriate for the use on a balcony surface. Certain materials, such as ceramic, can absorb moisture leading to cracking during freeze thaw cycles. Therefore, proper selection of low absorption materials is critical to the long-term maintenance of the tile. Tile sealers are also available in the market that will help to prevent moisture absorption. Tile sealers typically require reapplication every 4 to 6 years.

Failure of the grout, either by deteriorated or cracking, will allow moisture to penetrate beneath the tile where it will be trapped again the balcony slab. Freeze thaw action with cause further deterioration of the tile. Proper maintenance of the tile and grout is important.

We recommend that the installation of tile be incorporated with either a concrete sealer or membrane to provide added protection in the event the grout joints in the tile fail.

Removable Tiles

Removable tiles typically consist of a plastic base with a finished surface of composite, wood, or stone. They come in a variety of colours and sizes and easily to install. The tiles are loose laid onto the surface of the balcony and snap together to form a continuous flooring cover.   The plastic base elevates the tile away from the surface of the balcony allowing moisture to drain.   Removable tiles can be left in place all year round.

For a condominium owner, it’s important to consider that the balcony of your unit is commonly an exclusive use common element. Modifications to the balcony or application of coverings may require Board approval. Make sure to speak with your Board or Property Manager prior to completing any modifications to your balcony.

 

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The Pitfalls of Deferring Maintenance and Repairs in Condominiums

Condominium Engineering owners and directors are typically more aware of the maintenance costs and requirements of their buildings than their freehold-living counterparts. This is by virtue of legislation requiring that common element maintenance and replacement plans be considered through regular reserve fund studies.  However, like the freehold owner who elects to put off their roof replacement until next year, condominium corporations have also frequently elected to defer maintenance obligations, typically due to financial constraints, in the hopes that they won’t be subject to one of the pitfalls of deferred maintenance programs.

Deferring maintenance can have measurable short term gains. Delaying repairs or replacement to building components or systems can be done to provide cash flow relief, meet budgetary expectations, or delay the non-financial impact of the project.

However, deferring maintenance also comes with risks and potential costs.  Below I discuss 4 potential Pitfalls of deferring required maintenance.

Pitfall 1: Lack of consideration of the risks associated with emergency failure

Properly forecasted and planned replacement and repair projects consider construction variables such as urgency and material delivery time. There are numerous systems throughout condominium engineering complexes that require continuous operation and greatly affect the community in the event of unexpected failure. While considering deferring a repair or replacement project, a corporation must address the risk, adverse impact, and the additional costs that an emergency failure of the system could impose during the deferral period.  

Envision a main breaker switch replacement that is deferred due to immediate budgetary issues. Properly planned, any scheduled shutdown of the power during the project is addressed by notification to the owners or by arrangements of temporary power. In the event of emergency failure, the risks associated with the potential lack of availability and costs of emergency power, coupled with the additional strain of dealing with a community that just lost power may be worth re-evaluating budgetary priorities on aging equipment where the negative impact of unexpected failure is so great.

Pitfall 2: Uncontrolled or concealed continual degradation

Individual building elements are part of an overall system that rely on the integrity and proper functionality of all components. A failed caulking joint around a window can lead to water infiltration that damages drywall and saturates insulation, resulting in heat loss at the wall assembly. Deferring maintenance of elements where the failure is damaging other, sometimes concealed, secondary elements without proper consideration of the costs and impacts of repairing these secondary elements will often result in significantly increased future maintenance and repair costs.

Consider a multi-level parking garage, where intermediate slab and landscape covered podium slab membranes have been knowingly leaking for years. Membrane repairs have been deferred because the comprehensive proper repair involves significant work to localized areas of membrane failure. In the interim, tarps and eavestroughing have been attached to the ceiling of the garage to manage the penetrating water and ensure it is not dripping onto cars below. Large cracks in the slabs have received a polyurethane crack injections. These interim measures can be installed for years in order to defer (and turn a blind eye to) a parking garage renewal project, however, as the concrete continues to be penetrated with water containing chlorides and chemicals, it will degrade at an accelerated rate. Concrete repairs cost make up a significant portion of any parking garage project and the time associated with executing and curing the concrete repairs are the largest factor when determining how long the garage will be partially or fully closed to traffic.

Countless localized and minor repairs projects have spiralled into large, multi-year, costly, and disruptive projects under the guise of deferred maintenance.

Pitfall 3: Ignorance to volatility of material costs

Reserve fund plans and condominium budgets expect costs to increase over time in line with inflation. When evaluating future costs of deferred maintenance, condominiums often look to the local construction price indices which indicate year over year general inflation. However, materials or equipment that are related to a specific commodity, such as aluminum in high-rise windows or petroleum in asphalt, may see price increases over a relatively short period of time that fall outside the range of the general forecasted inflation rates.

Window frame replacement projects that were deferred from 2013 to 2015 would have expected a general construction price increase of 2.3% (Statistics Canada), however, aluminum prices varied significantly in this period, increasing by 17% at their peak. Although aluminium does not make up the entirety of these projects, over a 2-year period, the changes in material costs affected overall construction costs, resulting in an estimated increase in project cost of 6%. These unexpected changes could negate the original benefits of deferral altogether.

Pitfall 4: Life-extending repairs associated with deferral does not return an appropriate benefit

Occasionally, useful service lives of aging elements can be extended with minor to moderate repairs, thus reasonably deferring their subsequent major overhaul or replacement. The cost and scale of these life-extending repairs must be evaluated in relation to the benefit or savings of their deferral. The cost of the life-extending repairs may not be reasonable when considering the amount of time that the repairs defer the subsequent project.

Older aluminium window systems, depending on their exposure and use, have a typical service life of 35-50 years. As they age, the insulated glazing unit seals fail, their external sealants deteriorate, their hardware and mechanisms fail, their locks seize, and their weather stripping is no longer functional. These failures can result in decreased overall performance exhibited by heat loss, air exfiltration, and water penetration. All these elements can be replaced without replacing the frames; glass can be replaced with new, hardware can be swapped out, mechanism can be lubricated. The cost of these refurbishments will always be significantly lower than a complete window frame replacement, however, if the value of the refurbishment is 35% of the value of the future replacement, and is only expected to extend the service life of the windows by 25%, consideration should be given to dealing with the window elements as a whole, without delay.

Managing Risk

Deferring repairs and assessing priorities is a part of building management and operation. The money isn’t always available every year, and if it is, it may not be in the best interest of the community to carry out a specific project at a given time. Ontario condominiums are fortunate that with a comprehensively monitored and followed reserve fund plan, a reasonable contingency, and a detailed eye towards an appropriately managed maintenance contract, the need for deferral is often mitigated.

All project deferrals contain risk, which are evaluated by the probability of failure in relation to the impact of failure. In the examples above, we’ve suggested cases where the risks were either improperly managed or ignored altogether. A comprehensive review and preventative maintenance inspection should be performed when considering any deferral to ensure that you do not get trapped in one of the pitfalls.

 

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Sources: Statistics Canada, CANSIM, Price indexes of apartment and non-residential building construction, by type of building and major sub-trade group, 2016-11-08

Are Your Roof Anchors Ready for Window Washing This Spring?

“The windows are scheduled to be washed next week! But have the roof anchors been certified for use?”. We occasionally encounter Property Managers who require a roof anchor inspection that forms a part of their fall arrest system. Often, they are not aware of whether they need a visual inspection or load test or that the certification of fall arrest systems is required by law.

Understanding a building’s roof anchor maintenance and inspection requirements is not difficult, and with relatively little effort, Property Managers can automate this process in 3 easy steps.

 

  1. Know what type of anchors you have and what your requirements are.

The building’s initial design drawings or the roof anchor plan will identify the type, attachment, and purpose of the roof anchors and fall arrest system. Not all fall arrest systems are designed for swing stage use.

There are various types of anchors and components that may form part of your fall arrest systems, such as Davit arms and horizontal lifelines, however, for the most part, we see 2 types of anchor points:

Figure 1. Wall Mounted Anchors Figure 2. Pedestal Anchors

 

The Corporation’s anchor plan will identify whether you have adhesive, expansion, or mechanically fastened anchors. Typical examples of pedestal anchors are:

Figure 3. Adhesive anchor (note bolts embedded in slab) Figure 4. Mechanically fastened anchor
(note bolts through slab and fastened on underside)

 

The Health and Safety Code for Suspended Equipment Operations stipulates that, at a minimum, all anchors must be inspected at intervals not exceeding 12 months. This annual, visual inspection requires the inspector to:

 

  1. Review the design drawings to ensure compliance with current regulations, standards, and engineering standards – Did the plan make sense?
  2. Assess the system to ensure compliance with the engineered drawings – Did they install the anchors according to the plan?
  3. Inspect all exposed, visible, and accessible components of the system for signs of distress – Are the anchors in good conditions?
  4. Inspect all adhesive and expansion fasteners – Were the anchors requiring occasional load testing included in this inspection?

 

Where mechanically fastened anchors are attached to the structure using welds or fastened bolts typically require only the annual visual inspection, the standard requires physical load testing of adhesive or expansion anchors at intervals not exceeding 5 years.

The idea behind this additional requirement for adhesive or expansion anchors are attached to the structure by adhesive (glue) or forces induced by expansion (friction, wedge pressure) and are more prone to non-visible methods of failure. Putting these anchors under a specified load and ensuring that the anchors are not permanently deformed confirms the integrity of the conceal attachment system.

Anchors are loaded to 50% of their design loads, to provide a suitable degree of stress without compromising the anchor by loading it to failure.

The 5-year load test will require more time on site for the inspection, wherein they will bring appropriate equipment to load the anchors and measure any deflections. A typical loading set up is shown below:

Figure 5. Typical loading apparatus between pedestal anchors

 

  1. Know who can inspect and who can repair the anchors.

The standard mandates that either the visual inspection or the load tests be completed by a professional engineer, or a qualified person under the supervision of a professional engineer. There are several general building engineers and roof anchor inspection companies that can provide this service.

Following visual or loading inspections, the report may determine that minor repairs, such as caulking or flashing failures, or major repairs, such as anchor replacement, may be required. Depending on the level of complexity of these repairs they may require a simple handyman or the involvement of a design engineer.

If a Property Manager is unsure from whom to obtain an inspection or load test, they can seek recommendation from their general building engineer, their window cleaners, or their roof anchor manufacturers.

 

  1. Schedule your inspections.

Although roof anchors must be certified for any work that will require attachment (caulking replacement from swing stage, pre-cast panel inspection from bosun’s chair, etc.), typically the inspection is scheduled to be completed before the first window cleaning of the season. Recalling that varying degrees of repairs may be required following the inspection, we recommend that Property Managers look to schedule their annual inspection during the month of March or April.

Many anchor inspectors and certifiers are now offering 3-5 year inspection programs, wherein the inspector is engaged to preform all inspections (annual visuals and load testing) with the requirement that they will be completed each year without explicit annual authorization. This approach reasonably shares the requirement of ensuring regular annual inspections with the contracted inspector and allows for cost savings as the inspector benefits from previous annual work they have performed.

 

Important things to remember:

  1. Building or anchor plans will indicate the types of anchors on the roof.
  2. All anchors must be visually inspected every year.
  3. Adhesive or expansion anchors need to be load tested every 5 years.
  4. Qualified inspectors under the supervision of a Professional Engineer may preform the inspections and load test.
  5. Annual scheduling or pre-contracting inspection services helps ensure that the fall arrest systems will always be compliant.

 

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Efflorescence: That Annoying White Stuff on Masonry Walls

Introduction

You’ve seen it on a lot of buildings, perhaps even at your Condominium Corporation.

That white powdery substance is called efflorescence, it’s a deposit of soluble salts which is most obvious during the winter, but may also be observed throughout the year following heavy rains and sudden drops in temperature.

Often, it is apparent just after the structure is completed when the designers, builders and owners are most concerned with the appearance of the new structure.

The Causes

Efflorescence is caused by a combination of three factors.

First, there must be a soluble salt in the masonry. Second there must be moisture present to dissolve and transport the salt to the surface. Third, there must be some force such as evaporation to move the solution. If any one of these factors is absent, efflorescence will not occur.

 

Sources of Salts

There are many sources of salt, including clay bricks, concrete blocks, mortar, admixtures and ground water. Efflorescence-producing salts are usually sulfates, carbonates, sodium bicarbonate or silicate. However, almost any soluble salt, such as chlorides, nitrates and others, may appear as efflorescence. Since chloride salts are highly soluble in water, rain will often wash them off the surface of the masonry wall.

On occasion, there is also something called “green stain”, the result of certain vanadium and molydenum compounds present in some ceramic brick units. “Brown stain”, on the other hand, is mostly the result of manganese deposits.

Studies have shown that even very small quantities of water-soluble salts in the masonry may lead to efflorescence. The amount and character of the deposits vary according to the nature of the soluble materials and the atmospheric conditions.

Efflorescence is particularly affected by temperature, wind and humidity. For example, in the summer, even after prolonged periods of rain, moisture evaporates so quickly that only small amounts of salt are transported to the surface.

During the winter, however, slower rates of evaporation lead to the migration of salts to the surface. Normally, with the passage of time, efflorescence becomes less prominent unless there are external sources of salts.

In most cases, efflorescence causing salts are from the building materials used during construction, namely the masonry units and the mortar. Sodium and potassium hydroxides are commonly present in portland cements and may cause some efflorescence during the first year after construction. This is known as “building-bloom”, a condition which typically disappears after a short while.

 

Sources of Moisture

After the initial construction, as the masonry dries out, the exterior walls may display “building-bloom” for the first few months. Typically, rain will remove this efflorescence and after one or two seasons, the blooming effect will disappear. However, where efflorescence persists, the continuous sources of moisture should be identified and controlled.

Water is the solvent for the efflorescence-producing salts. It is the vehicle by which the salts are transported to the surface where they accumulate as the water evaporates. The primary source of moisture is rain water, and particularly driving rains which deposit substantial amounts of moisture in the masonry walls.

Another major source of moisture is leakage of moist air from the building interior. Such leakage is frequently possible due to discontinuities in the air and vapour barriers which will permit exfiltration of moisture-laden air through the exterior wall components where they will condense on colder surfaces. Such moisture then migrates to the masonry surface by capillary action.

Air leakage in buildings can occur at sills, headers and around rough openings cut to accommodate doors and windows, around plumbing stacks and openings for electrical outlets. It can also occur at the top of partitions, where the vapour barrier is frequently discontinuous.

Is it Harmful?

In general, efflorescence in the form of surface deposits is not harmful to the masonry walls, but the disfiguring staining is annoying to owners and may affect property and rental values. If efflorescence persists beyond the initial period of “building bloom”, the sources of moisture must be investigated. Where abnormal wetting occurs due to poorly located drains and scuppers, missing copings and drips or deteriorated caulking, these deficiencies can be readily rectified.

Where efflorescence is caused by air leakage, remedial repairs are frequently difficult to carry out and expensive since they entail the repair of air and vapour barriers and involve the interior finishes. Therefore, the advise of a professional engineer specializing in building science issues should be obtained for a careful assessment of the as-built conditions before remedial actions can be formulated.

While a number of surface treatments are commercially available to help control efflorescence, they should be used with caution. Most surface treatments act as water repellents which reduce the formation of efflorescence. This is partly due to the fact that less moisture is able to enter the masonry and partly due to the evaporation of soluble salts occurring just behind the treated surface layer, and this is where serious problems can occur.

As the salts crystallize and accumulate behind the treated surface layer, pressures can build up which may lead to spalling of the masonry units. Therefore, surface treatments may be successful only if they are carried out in conjunction with other measures which will control the amount of moisture entering the masonry from the interior.

Removing Efflorescence

Once the cause of efflorescence is corrected, the removal of the deposit is relatively easy, since most efflorescing salts are water soluble. In general, efflorescence can be removed by dry-brushing followed by flushing with clean water. If this is not satisfactory, walls can be washed with a five to ten percent solution of muriatic acid. It is always advisable that a small inconspicuous test area be tried first to determine whether etching or other discolouring will occur. After the acid treatment, the surface should be immediately and thoroughly flushed with clean water.

If chemicals are used, shrubberies and plantings along the building perimeters should be well protected or removed. It is also advisable to ascertain that the contractor assigned this work is experienced and to check a few references. Acid treatment of masonry walls can do more harm than good if wrongly applied.

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