An Ounce of Prevention is Worth 34'000 Pounds of Cure

I thought long and hard about what would be the topic for this entry. I've encountered a few things since I last talked to you and many have been considered. But when I encountered the situation I'm going to describe to you, the choice was clear that this had to be shared. The reason is because this prevalent problem can be prevented so very easily and yet, after the fact, will be so expensive to fix. The ultimate “stitch in time saves nine”, “ounce of prevention saves a pound of cure” or whatever colloquialism suits your fancy that basically describes the monumental error of pouring a driveway the completely wrong way.

 

Concrete driveways are many and varied. Different colours, strengths, thicknesses, pitches, patterns etc. But what is shared between all concrete pours is a need for movement. Concrete needs room to expand and contract with the changing climate. Even a person with no interest or experience with concrete has most likely walked down a sidewalk and noticed the lines running perpendicularly through the sidewalk at very regular intervals. There are two types of joints here. One is a control joint. A joint that does not separate two sections of concrete but creates the weakest point in the slab and thus, where the slab will inevitably crack. Keeping the crack neat and tidy. The second is a complete separation of slabs that goes all the way through. These joints, called expansion joints, usually have an asphalt soaked fiber material (or recycled rubber) in them to fill the gap and allow the two adjacent sides to move independently as needed. These are invaluable and should be found about every ten feet.

 

Today's example is not a sidewalk, it's a driveway. But the principles are exactly the same. So what does every driveway need? Room for expansion, contraction and movement with the climate. So let's take a look at one. The driveway pictured was poured tight between two large buildings. With no expansion joint separating the driveway from these buildings. Can a driveway possibly move in between these anchors points that are much more firmly planted? Well the answer is yes. Sorry that is sort of a trick question. But the problem is that it can't possibly move in the way we would like. Which leads us to the cracking. When it rains, water pools against the building at the driveway edge, soaking underneath and collecting there. When the water freezes it heaves the slab up. The only problem is that the slab is anchored to the sides of a sturdy building. So the slab heaves in the center, but not at the edges. Resulting in the badly cracked, crowned slab we see here and water damage to the sides of the buildings too. With the driveway higher in the center than the edges, the water is encouraged to flow up against the side of the buildings, over the joint that allowed it underneath in the first place and further exacerbates the problem. The only solution at this point is to remove all this failed concrete and pour it the right way. A very costly mistake that could have been prevented with a slight design change.

 

How should this driveway have been poured? Not up against the buildings! And with not even a HINT of pitch towards those buildings. Here's how I would have done it. I would have placed a trench drain (pictured above)right in the center of the driveway and then poured on each side of it with a 2% slope UP to the buildings. This way, any water on the driveway will be directed to the center of the driveway to a drain instead of up against buildings. I would have also placed expansion joint material between the buildings and the driveway to facilitate movement. This joint can be sealed over with a quality caulk to further protect the building from water seeping through that joint. But with our proper pitch, this is less critical. This drain exit can be connected to a storm drain, bubbler or run to low ground with erosion protection. Problem solved. Had this been done at the time of construction there would be no problem. But now this driveway has 34'000 pounds of failed concrete (8.5c.y.)that needs to come out and be repoured the right way. There is no easy or cost effective way to correct this problem. The concrete will not settle back down to a proper pitch and sealing the cracks will not eliminate the water sitting at the sides of the building.

 

The moral of the story? Spend a little more up front and save yourself a ton of headaches, property damage and cost down the road. It's not worth cutting corners to save a few bucks because it will always come back around to bite you. You can pay a little more now, or a lot more later. Consult reputable professionals who know what they're talking about and listen to their advice. Get multiple opinions and compare the responses. Ask contractors about things the others have told you. Guage the responses. And of course, do some research yourself to at least somewhat familiarise yourself with the project in question. You wouldn't go buy a car without knowing how to drive right? Well don't get major projects done on your house if you don't know at least a few basics from the outset.  

Posted on March 24, 2015 .

Chimney Crowns: Right and Wrong

 Hello and welcome to my first blog entry. I have already introduced myself in the biography section of this site but my name is John Bard. The purpose of this blog is to discuss anything and everything masonry related and I will try my best to stay on topic. I will try to share some current or past projects with photos. This will be a place where the reader can gain some insight into masonry and the challenges and rewards of utilizing it in a building. I plan to bring useful information to homeowners including money saving tips and maintenance techniques as well as discussion aided by photos to help people to understand what goes wrong where and why. Masonry represents a large part of any building. As such it is a large initial investment by a building owner and can represent a huge cost in repairs and restoration prematurely if the proper techniques were not adhered to at the outset. Questions from readers area always welcome. For the first post I thought I'd talk a bit about where we are at right now in the year. Winter... Not too many masonry projects happen this time of year as it requires tarping in and heating the work area. Down south they don't have to worry about this but they have their own environmental factors to consider which will be discussed at a later date. This encapsulating of the work area and providing heat adds costs that can be simply avoided by doing the job when the season is more appropriate. And so this time of year is never too busy. So generally, winter provides me with a sort of professional development [unpaid] holiday to better myself and the business. I suppose I can't really complain about winter too much however since the season that forces me to slow down for three months out of the year, also creates much of my work for the rest of it. Let me explain. Have you ever tried to rapidly chill a drink in a glass bottle by putting it in the freezer, but then forgot about it? What happens to that bottle? It breaks from the fluid inside freezing and expanding. Simple science, but integral to understanding the beating that buildings take in a northern climate. This problem isexaccerbated by the fact that it rarely just stays below freezing forthe whole winter season. The temperature goes up and down and this freeze thaw cycling doesn't play nice with masonry. As tiny cracks develop, some of which may appear within days of doing the job due to poor technique, moisture can gain access to these cracks. This moisture sits in these little cracks just waiting for the temperature to drop below freezing and then it freezes, expands and pushes the crack surfaces apart making the little crack slightly larger. When it warms up, this moisture melts and settles again, occupying the new, slightly larger space, waiting for another freeze to expand it once again. And on and on it goes. This may seem elementary, but if left alone, it can devastate masonry structures. I provide a photo I took while standing on the top of a chimney inspecting it. You can clearly see the crown is split in pieces and water just pours in through the top of this, furthering the problem. When a chimney gets this far gone, the deterioration will be quick. Bricks and pieces of crown can fall off and damage roofs, adjacent buildings and people that may be underneath. So what is the solution? A SOLID concrete crown, not a thin concrete skim over brick like the one pictured and certainly NOT a mortar wash crown. The crown should overhang the masonry by at least 1.5”. It should have an expansion joint against all flues so that they can expand and contract as needed. And it should have a noticeable pitch on the top to drain water off the sides and prevent pooling on top. Finally, any small cracks that are caught by a yearly inspection should be sealed right away to prevent further water penetration. 

Posted on January 22, 2015 .