CustomConcrete.biz Blog

How pervious concrete can improve stormwater drainage around a home under construction

dave@customconcrete.biz (Dave Johnson) — Wed, 18 Jan 2017 02:45:57 GMT

Are you building a house in the city limits of Bellingham? It wouldn’t surprise us in the least if the City of Bellingham has told you that you need to install pervious concrete on your property. This has been happening more and more lately.

The reasons are plenty, but the main one is this: Impervious surfaces, such as roofs, traditional concrete and asphalt, create massive amounts of runoff, which puts an often-unbearable load onto local stormwater systems.

This is where pervious shines.

Believe it or not, as much as 5 gallons per minute can pass through a square foot of pervious concrete. That’s a rate fast enough to handle 8 inches of rainfall every 60 seconds!

In Whatcom County, 8 inches of rain in a month is a huge amount. But drainage systems do get overburdened quite often in heavy storms, especially as water runs off of roofs, roads, driveways and other impervious surfaces and is collected by downspouts and drainpipes into certain areas.

For example: A house with 2,500 square feet of roof area, in a storm that’s dumping an inch of rain per day, is collecting a little over one gallon of water per minute. That’s an awful lot of water, but with the aid of pervious concrete, it’s possible to handle all of the water without even taxing the city’s stormwater system.

Related: Want to run your own calculations on the amount of water produced by a certain storm? The USGS has created a handy calculator for this purpose.

When installed by a knowledgeable, licensed contractor, pervious concrete can be a huge help in managing drainage, runoff and stormwater issues.

The prevention of runoff is one major benefit to pervious concrete. But that’s not all. Here are a few other ways that pervious can benefit a home under construction:

As a filter for pollutants: Research has shown that as much as 99 percent of oils that drip onto pervious pavements are trapped by the voids in the pavement and biodegraded before they even reach the underlying soil. On the other hand, oil that drips onto traditional pavements is often carried away by runoff, potentially polluting nearby bodies of water. Because pervious concrete captures the “first flush” of rainfall and allows it to seep into the ground, the polluted water can be treated by natural processes. Costly and land-consuming stormwater retention areas, then, may not be needed.
As a drainage border: A relatively narrow strip of pervious around a conventionally paved area, such as a driveway or parking lot, can significantly reduce runoff. Water may sheet off of the main surface, but when it gets to the edge, it seeps into the ground. This is a great way to reduce the need for water management systems and reduce the load on city services.
As a water recharger: One of the biggest problems with typical stormwater systems is that the rainwater collected in one area -- on your property, say -- is piped off to be handled at another location. Over time, the water table under your property can be diminished. Pervious concrete, though, allows water that falls on your property to seep into the ground and recharge the water table on your property.

The pros at Custom Concrete Contracting are experts in all things concrete. They can install traditional concrete foundations, footings and retaining walls, and they’re also Northwest Washington experts on pervious concrete. Give them a call today to discuss how pervious concrete can benefit your construction project.

Feature project: Building a traffic circle in Sedro-Woolley

dave@customconcrete.biz (Dave Johnson) — Fri, 23 Dec 2016 20:33:53 GMT

As of 2015, Washington state was home to roughly 307 roundabouts. For almost every Washingtonian, they’ve become a familiar part of our daily travel routine.

But two decades ago, in 1997, the number of roundabouts in the state was… 0.

It’s not just your imagination that roundabouts have been appearing all over the state in recent years. According to the state Department of Transportation, all of the state’s roundabouts were built in just the last 20 years, and many more are on the way.

Custom Concrete is OK with that. We’ve done a number of roundabout jobs over the years, including this one at Northwest Avenue and McLeod Road a couple of years ago that made heavy use of pervious concrete.

We’ve just completed our most recent roundabout, a traffic circle at the spot where Highway 9 intersects with Jameson Street and Rhodes Road in Sedro-Woolley.

The job was part of a public works project for the city, which for several years had identified an extension of Jameson Street to Highway 9 as a major public need. For the four-way roundabout section, which joins a well-traveled highway to two side streets, we used stamped, red-colored concrete. The large roundabout included 585 square yards of colored truck apron, which we stamped to emulate the look of textured red pavers.

In addition to the traffic circle, the project included an extension of Jameson Street through commercial property near Sedro-Woolley High School. We installed 2,100 square yards of brush-finished concrete sidewalk along the new street in addition to curbs, gutters and driveways.

The primary goal of this project, according to the Skagit Valley Herald, was to increase access to the city from Highway 9 while also improving vehicle and pedestrian safety near the high school.

As always, Custom Concrete Contracting is proud to work with local municipalities to improve the lives of our friends and neighbors. If you’d like to chat about how we work as a subcontractor on commercial and public works jobs in NW Washington, just give Dave Johnson a call.

Feature project: Building a pervious driveway in Bellingham

dave@customconcrete.biz (Dave Johnson) — Tue, 06 Dec 2016 19:47:21 GMT

We’ve been doing a lot of work lately to make our pervious concrete processes even better, and we were excited to get to show it off on a recent job.

Custom Concrete Contracting was hired to do some pervious concrete work for a construction project manager in Bellingham. Because of the size of his property he had to install a pervious driveway instead of the traditional concrete driveway.

You might be aware that the City of Bellingham has special rules for building on property. According to Bellingham Municipal Code 16.80.090, impervious and partially pervious surface areas are limited. Together, the two -- impervious and partially pervious -- can take up no more than 2,500 square feet or 25 percent of the total lot area.

Note: There are a few exceptions to this general rule, such as for those whose property drains into Basin One of Lake Whatcom, so before you get started, be sure to get in touch with the city regarding specific rules for your property.

In this case, the homeowner was required to install a pervious concrete driveway -- considered a partially pervious surface by Bellingham code standards -- in order to be able build on his land.

Total impervious square footage alone is limited to 2,000 square feet. In some cases, choosing pervious concrete for the driveway, instead of traditional impervious concrete, means that the footprint of a newly constructed house can be bigger. That can be good news to land owners who want to maximize the use of their property.

What’s even better is that Custom Concrete has refined its process to make pervious concrete even more smooth, even and beautiful. CCC’s pervious concrete jobs now look more like traditional concrete than ever.

As you can see, we went with pervious in the center areas of the driveway and installed a dark gray, stamped border that looks like Italian slate. We also used pervious on the walkway to the front door and extended the Italian slate motif to that area as well.

The hillside slope also makes this job a great candidate for pervious concrete, because it’s less susceptible than traditional concrete to freezing. Thanks to all of the pores in pervious concrete, air can circulate and help melt snow sitting on the surface. Additionally, any water that would otherwise freeze on the driveway is allowed to filter through to the ground beneath.

If you’re building in the Bellingham city limits, consider the benefits of using pervious concrete for your driveways, walkways and patios. Perhaps you can bump up the size of your new house or add an extra garage. Or you could simply use pervious for the benefits it has on the environment by decreasing runoff, especially so near Bellingham’s drinking water supply.

Contact Custom Concrete today to learn more about ways pervious concrete can benefit your residential construction project.

Feature Project: Connecting neighborhoods in Bellingham, WA

dave@customconcrete.biz (Dave Johnson) — Wed, 19 Oct 2016 18:08:26 GMT

Another fun, community-building project is in the books! Custom Concrete Contracting recently completed a pervious concrete contracting job for the City of Bellingham’s Public Works Department. Two neighborhoods up on the hill in the Barkley area in Bellingham needed to be connected via sidewalk, and we (of course!) were the right company for the job.

The bulk of the project included installation of 164 feet of pervious concrete trail connecting two neighborhoods. The new trail replaces an old footpath that had been worn through the underbrush.

Because pervious concrete is water-permeable, the project gives pedestrians a clean, mud-free walking path without contributing to stormwater issues.

Did you know the US Environmental Protection Agency (EPA) reports that because permeable pavements allow rain and snowmelt to seep through the surface and into the ground, permeable pavements can soak in up to 80 to 100 percent of the rain that lands on them and filter out pollutants in runoff that would have otherwise contributed to water pollution.

At the southeast end of the path, Custom Concrete crews installed a concrete staircase and landing, including a hand rail for pedestrians and a sweet little bike ramp for riders.

We love doing projects like this for the City of Bellingham, because they beautify our neighborhoods and make an immediate impact on the quality of life around here. Our concrete flatwork finishing company was chosen by the city for this job from among the public works bids submitted, evidence that Custom Concrete does top-notch work at a competitive price.

If you are project manager for a NW Washington construction team, and you’re looking to subcontract some work to a highly qualified, highly skilled Bellingham concrete subcontractor, please consider contacting a member of our Custom Concrete team. We’re here to help get your next job done right -- on time and on budget.

Myths and facts about pervious concrete

dave@customconcrete.biz (Dave Johnson) — Tue, 20 Sep 2016 16:02:00 GMT

Though not exactly new, pervious concrete is innovative and exciting. It offers a durable parking and driving surface that simultaneously reduces runoff by allowing water to filter directly through it. That has to be too good to be true, right?

Certainly, there are a lot of people out there who would say so. But some of the negative things we hear them saying about pervious concrete just aren’t true. Here are a few common myths and facts about pervious:

Myth: It's too expensive.

Fact: The actual installation cost of pervious alone can indeed be higher than its traditional counterpart, but pervious can reduce the overall costs of residential and commercial projects by reducing the need for other drainage features. Because pervious concrete allows rainwater to drain directly through to underlying soil, less stormwater management is needed with pervious installs.

Myth: It won’t last as long as traditional concrete.

Fact: When installed by certified pervious installers, pervious has a fantastic longevity. As with any concrete product, how long it lasts has to do with the quality of installation. Occasionally, longevity also can be tied to the concrete mix, which is usually decided by the engineer on larger projects. On such large, commercial jobs, project engineers choose the mix based on the requirements of the project. Pervious concrete has also been shown to be more durable than its asphalt counterpart.

Myth: The “pores” will clog.

Fact: The key here is maintenance. No concrete is maintenance-free. It’s a common concern that plants might grow in the pores of pervious concrete, but that shouldn’t happen with a well-maintained installation. Pervious concrete is just like a boat. You have to clean it periodically, or gunk builds up that decreases performance.

Modern pervious concrete vacuum systems can pull clogged stuff out, even if it's been there a while. Even if pervious concrete pores get clogged, there is a way to clean them.

Myth: It won’t stand up to heavy or commercial use.

Fact: A pervious driveway is just as durable as any other concrete driveway. The key here, for both pervious and regular concrete, is that the pour is thick enough to handle the expected traffic. Custom Concrete will pour 5- to 6-inches thick on some projects instead of the standard 4 inches if the load will be heavier. Most parking lots, for example, will be at least 6 inches thick. At Meridian High School in Bellingham, WA, Custom Concrete installed pervious 8 inches thick because fire trucks and buses would be using the lot to turn around. On commercial projects, engineers design the surface thickness to handle the traffic that’ll be using it.

Myth: Snowy conditions clog pervious concrete.

Fact: Actually, the opposite is true. Because of its porous nature, pervious concrete increases airflow and helps melt snow more quickly. It’s totally fine to use shovels and snow plows on pervious, too. Just make sure the scoop has a rubber edge, so you’re not using metal to scrape the concrete surface.

Myth: It's a fad, and it soon will go away.

Fact: Cities and counties nationwide say pervious is the way of the future. Municipalities all over Washington state are investing in it and planning for it. In fact, most of the pervious installs done by Custom Concrete are for governmental agencies.

Ready to talk to local experts about the benefits of installing pervious concrete in Northwest Washington? Contact Custom Concrete Contracting in Bellingham, WA. They employ NRMCA certified pervious installers and technicians.

Pervious concrete is a viable option for LEED projects

dave@customconcrete.biz (Dave Johnson) — Wed, 17 Aug 2016 19:30:00 GMT

Did you know that using pervious concrete in your next construction project could help you earn LEED certification?

It’s true. The use of pervious concrete can earn points in several categories, most notably the area of Sustainable Sites. We’ll explain how below.

But first, a LEED primer.

The acronym stands for Leadership in Energy and Environmental Design. In 2000, the U.S. Green Building Council published a series of goals that, when achieved, make a building more sustainable and resource-efficient. Construction products can be LEED-certified at four levels: platinum, gold, silver and certified.

LEED certification contains six main categories in which projects earn points for achieving certain benchmarks: Location & Transportation, Sustainable Sites, Water Efficiency, Energy & Atmosphere, Materials & Resources and Indoor Environmental Quality. Each category is divided into credits that describe the intent, requirements, technologies and strategies for meeting each credit. Those credits are further broken down into individual points.

Something new in LEED v4, the current version released in November 2013, is that runoff from precipitation isn’t even referred to as a waste product anymore. Gone is the “stormwater” appellation; it’s now simply referred to as rainwater.

“Managing rainwater on-site restores natural hydrologic conditions, reduces the possibility of flooding and creates opportunities for on-site water reuse in applications such as irrigation and landscape features,” according to the USGBC.

In explaining the new Sustainable Sites category, the USGBC cites a study from the Washington State Department of Ecology that claims that rainwater runoff from roads, parking lots and other similar features carries around 200,000 barrels of petroleum into the Puget Sound every year -- more than half of the total from the 1989 Exxon Valdez spill in Alaska.

So, how can pervious concrete help earn you LEED credit?

The National Ready Mixed Concrete Association offers some great information on concrete and LEED credits. Here are the highlights:

The Site Development―Protect or Restore Habitat credit in the Sustainable Sites category aims to conserve existing natural areas and restore damaged areas to provide habitat and promote biodiversity. Using a pervious concrete parking area to store and treat rainwater, thereby eliminating or minimizing land required for detention ponds, helps protect and restore habitat.
The Rainwater Management credit in the Sustainable Sites category aims to reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of the site using low-impact development. Because pervious concrete pavement increases infiltration, it can improve the rate, quantity and quality of stormwater runoff.
The Outdoor Water Use Reduction credit in the Water Efficiency category requires the reduction of outdoor water consumption through the use of landscape that does not require permanent irrigation or through the use of alternative water sources. Pervious concrete systems and other concrete stormwater management systems, such as culverts and pipes, can be used to capture stormwater for collection into cisterns for irrigation purposes.

There you have it: A brief overview of how using pervious concrete can help earn LEED credits for your project. For more information or to get started, contact the pros at Custom Concrete, who have years of experience installing pervious pavement in Bellingham, throughout Whatcom County and around Northwest Washington.

The benefits of pervious concrete around landscaping

dave@customconcrete.biz (Dave Johnson) — Wed, 20 Jul 2016 22:00:00 GMT

Planning a large patio in your backyard? How about a new driveway? Or maybe a small pad for you and your kids to shoot some baskets?

There’s a lot to love about these ideas, but two things you don’t want are roots breaking through your new concrete or ground that’s too hot to walk on barefoot in summer months (yes, this happens, even in Bellingham and throughout Northwest Washington!).

Pervious concrete helps to mitigate these problems in two major ways:

Water drainage:

We've all seen this common problem: In search of water, tree roots break through traditional concrete sidewalks, driveways and parking lots, creating unsightly and even dangerous conditions.

But what if the roots had all the water they needed, no matter what was above them?

Pervious concrete helps prevent tree roots from lifting concrete because rainwater is disbursed through the porous surface, saturating the soil and ensuring roots have the water and nutrients they need.

Where pervious concrete is installed around landscaped areas, trees and shrubs don’t have to seek out water — it comes to them, evenly distributed right through the concrete.

Related: Pervious concrete also essentially eliminates harmful runoff. Oil dripped onto traditional
concrete, for example, is washed right into storm drains, while more than 97 percent of oil
dripped onto pervious concrete is trapped and biodegraded before it even hits the soil.

Heat reflection and release:

Have you ever tried to walk across hot concrete with bare feet? It can be bad. Studies have shown that in the sun, traditional concrete can be 30 degrees Fahrenheit hotter than the air temperature. On those mild 80-degree days, the concrete can still be 110. And asphalt? Even hotter at 130! Ouch.

But because of the many small air pockets in pervious concrete, it doesn’t get nearly as hot. Air circulates through the concrete, and there isn’t the mass there to slowly heat up throughout the day.

One study from the American Society of Civil Engineers showed that the temperature of pervious concrete in full sun is equivalent to the temperature of traditional concrete in full shade. That can make a huge difference on hot summer days.

Related: Because of its cooling properties, pervious concrete helps to reduce the detrimental Urban Heat Island effect, which raises the temperature of both air and groundwater in urban areas.

Contact Custom Concrete today to learn more about the benefits of using pervious concrete for sidewalks, driveways and patios around landscaped garden areas.

Pervious concrete vs. porous asphalt, what is the difference?

dave@customconcrete.biz (Dave Johnson) — Wed, 15 Jun 2016 15:30:00 GMT

Concrete or asphalt? Urban planners and roadway engineers have been asking this question for decades. Depending on the specific needs of a community, both can be wonderful options.

Deciding between pervious concrete and porous asphalt can be a more difficult task. The key points to consider are initial and long-term costs, durability and maintenance. Each product shines in various areas. Despite its higher installation cost, pervious concrete's greater durability makes it a better long-term option than porous asphalt.

Durability: Studies show that concrete typically lasts a decade or longer than asphalt before repairs are needed.

Much more than concrete, asphalt is susceptible to raveling, or breakdown of the material. The Florida Department of Transportation conducted long-term tests of various roadway materials, concluding that while pervious concrete was a great option, porous asphalt was not, due to a high level of raveling.

Heat Retention: Asphalt retains more heat than concrete, and that heat causes asphalt to break down. And porous asphalt is even worse than standard asphalt. A study conducted by the National Center of Excellence at Arizona State University found that porous asphalt exhibited higher daytime temperatures than even traditional asphalt. Pervious concrete, on the other hand, actually has been shown to be cooler.

The University of New Hampshire’s Stormwater Center notes that pervious concrete has reduced daytime temperatures, thus minimizing the Urban Heat Island effect. The same is not true of porous asphalt.

Cost: Both pervious concrete and porous asphalt cost roughly 20 percent more to install than their traditional counterparts, with concrete costing slightly more to install than asphalt.

One reason for the higher installation cost of pervious concrete is that the concrete is laid thicker. In typical applications, pervious concrete is laid at a thickness of 6 inches, compared to 3 inches for porous asphalt.

Maintenance: Porous surfaces, whether concrete or asphalt, require different maintenance than standard surfaces. The UNH recommends sweeping and pressure-washing and quarterly vacuuming of both types of surfaces, in addition to regular visual inspections. Standard concrete requires much less maintenance than standard asphalt, but there isn’t a huge difference between the pervious concrete and porous asphalt in regard to maintenance.

Ready to talk to local experts about the benefits of installing pervious concrete in NW Washington? Contact Custom Concrete Contracting in Bellingham, WA. They employ NRMCA certified pervious installers & technicians.

The benefits of pervious concrete

dave@customconcrete.biz (Dave Johnson) — Fri, 20 May 2016 16:36:00 GMT

The main purpose of pervious concrete is to capture rainwater, evenly disburse it and return it to the ground.

When installed properly, pervious (or porous concrete) will reduce storm water runoff and provide environmental stability. It is also helpful in lowland areas where it can be used to reduce or prevent urban flooding.

One major benefit of installing pervious instead of traditional concrete is that it can reduce the overall costs of residential and commercial development projects by decreasing the need for other drainage features. Less storm water management is needed for pervious concrete, so the long-term cost may be cheaper than traditional concrete.

Check out this video to see it in action!

Need an environmentally-friendly paving surface? Pervious is perfect! Unlike regular concrete, pervious concrete can greatly reduce the amount of pollutants (fertilizers, pesticides, car oil, soaps, etc.) being carried to waterways and storm drains. This makes installing pervious a natural paving choice.

According to the US Environmental Protection Agency (EPA), permeable pavements allow rain and snowmelt to seep through the surface and into the ground--permeable pavements can soak in up to 80 to 100 percent of the rain that lands on them and filter out pollutants in runoff that would have otherwise contributed to water pollution.

Pervious concrete is relatively low maintenance. Like most concrete, sand, dirt or other debris can settle into the pores. Occasionally using a vacuum sweeper or pressure washer to wash off debris will keep the concrete looking great and functioning properly.

Contact Custom Concrete Contractors in Bellingham, WA to learn more about installing pervious concrete in Northwest Washington

Check out these previous projects completed by Custom Concrete:
Feature Project: Huntington Street Pervious Concrete Installation
Feature Project: Eco-Friendly Concrete at Bloedel Donovan Park
Featured Project: Pervious Concrete Driveway
Feature Project: Roundabout at Northwest Avenue & McLeod Road in Bellingham WA

Maintenance tips for pervious concrete

dave@customconcrete.biz (Dave Johnson) — Thu, 21 Apr 2016 19:30:00 GMT

Just like traditional concrete that you sweep or blow clean and pressure wash, pervious concrete needs maintenance too. Proper maintenance will ensure that your pervious cement keeps working as it should for a really long time.

See pervious concrete in action!

Ongoing maintenance makes sure the small spaces incorporated into the paving product (spaces that help water disburse and pass through) do not get clogged with leaves, dirt and other outside debris.

Maintaining the ability for water to flow freely through pervious concrete requires visual inspections, seasonal sweeping/blowing and deeper cleaning one or two times per year. Here’s what to do:

Maintenance plan for pervious concrete.

Frequently inspect for clogging to ensure that rainwater is properly draining.
Sweep debris regularly, especially after a windstorm. Clear away fallen leaves, pine needles and mud from wet winters in Northwest Washington.
Pressure wash pervious surfaces 1-2 times per year to remove any sediment from the changing seasons. Don’t forget to remove the sediment that is purged as well!
Keep piles of yard waste, mulch, sand, dirt, etc. off pervious surface and don’t change your car oil or use other types of chemicals over this surface.

Check out our pervious concrete gallery here.

Proper maintenance of porous concrete will help the environment and it will protect your paving investment. Homeowners and property managers can handle pervious concrete maintenance on their own or they can contract with a local concrete maintenance company to do the work.

Custom Concrete Contracting is the go-to source for installing and maintaining pervious concrete in Whatcom County. Our certified flatwork installers and finishers have worked on concrete surfaces in public spaces and private homes around our community. Contact us with any questions you have about pervious concrete.