Trench drain systems can be an absolute must-have during the summer or rainy seasons, protecting residences from water-clogging. As a homeowner, you may wonder about this term.
A trench drain system is exactly that – a basic system using a trench (open gutter) to ease the flow of water around your house. This is especially useful if you live in a low-lying area prone to excess water, or have heavy landscaping around your house. The last thing you want as a proud homeowner is to have your exterior walls damaged due to excess water collected over time.
In this guide, you will learn the basic process of building a trench drain system, and key factors to choose the best type to protect your home.
1. Why do you need a trench drain system around your house?
Your answer to this question will determine the size of your trench. For instance, trench drain systems can be as small as 6 inches wide, to a few feet deep (recommended for heavy-traffic commercial areas like airports). The trench that you will need to build around your home will more likely be 1-feet wide and 18-inches deep, which is more than adequate to stop and reroute seasonal water collection around your house.
On the other hand, if water collection is a chronic problem because you live in a low lying area, you may also need to pair your trench drain system with a sump pump in order to regularly keep your drainage from being clogged.
2. Where will it be placed?
This includes consideration of surrounding areas. For instance, if the area where you plan your trench is heavily landscaped, or even a part of your gravel parking area, you may also want to consider adding at least a couple of inches of concrete (at the bottom of your trench), for added strength and stability. Also, this will add 24 hours to the overall building process as this is the time needed for concrete to set.
3. How will it be laid out?
Is your trench layout a straight line, or will it include an intersection of more lines, perhaps forming a perimeter around your house? If so, you will also need to factor end caps for the shallow/connecting ends, so there is no water collection at the edges.
4. What do the building regulations say?
Many homeowners happily dig up a trench around their house to ease water clogging, and then find themselves in violations of local building laws. Make sure this does not happen to you. For this, it is advisable to make a layout plan of your proposed trench drain system, and run it by the local city council for approval. While this may be a tedious process (sometimes taking up a week or more), your local city council will be more informed of any problem areas lying around your house (like open sewer systems, etc.), and the impact your trench drain could have on it. Do plan for this process in advance.
5. What kind of drain do you need?
If it is a simple water clogging issue, a 4-inch diameter PVC pipe should suffice. Here, rigid-PVC pipes cost almost twice as much as their flexible counterparts, but are more durable and hence recommended for the long term. If you go this way, you will also need to consider glued-in fittings compatible with your pipe’s diameter.
6. DIY or outsource to a contractor?
A do-it-yourself trench drain system will obviously include a few hours of hard labor. On the other hand, you can also make it a fun weekend project including your close friends and family. With this, you can save several hundreds of dollars in contractor costs (providing you $$ for pizza for your hard working crew!).
Before you make this choice, it is still advisable to run your layout plan through an expert (including one from the city council) to ensure you are not inadvertently digging over the city’s drainage system.
7. Tools and accessories
Now that you have most of the key considerations out of the way, you are ready with your (own or outsourced) crew to dig your trench.
- Here, consider renting a trenching tool (typically $100 to $175) per day to help you ease the laborious task. This tool is powered by gas or electricity, and can dig up a decent trench (2-feet wide and 1.5-feet deep) in just a couple of hours.
- Most tools (including the trenching tool, or an ordinary shovel used for manual digging) will throw up a fair amount of dirt from the trench area to the side. Do plan for this in advance. You can create a barricade of sorts using tarp-material, which also makes it easier to collect the dirt after the digging process and relocate as required.
- Consider using the dirt collected for landscaping (like raised flower beds) to avoid wastage. People pay several $$ for this “dirt” during new construction!
- You can also consider lining your trench area with landscape fabric for extra protection.
8. Digging and filling the trench
Once you have your tools and accessories in place, the (almost) final step is digging the actual trench. Here, if your trench is in a concrete area, you can dig directly into the concrete, provided you are clear there are no underlying pipes or drainage systems below.
If you are digging within gravel/dirt/yard areas, consider lining the bottom of your trench (once you have dug it) with 2-inches of concrete for extra strength. Instead, heavy water flow through the drain can cause it to sink into the dirt over time, which in turn reduces its lifespan.
Once you are done digging the trench, place the PVC drain pipes such that there is a deep end and shallow end in order to ease water flow. This direction should also be printed/ painted on the drain pipe for easy access at a later time.
The final step lies in covering the drain. Here, you may either choose to fill the rest of the trench with dirt and gravel, or leave it as-is giving the pipes room to expand during summer.
9. Installation of grates
Typically, a trench drain system around your house may be small enough to not warrant grates (assuming it is secluded from human traffic). However, we strongly recommend installing them anyway to protect your pipes from corrosion. It will also provide a clean look to the trench drain system so it blends in with your house.