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Moisture Barrier Versus Interior Waterproofing: Which Do You Need?

exterior basement waterproofing

The moment you notice a moisture or humidity issue with your basement, your learning curve begins.

First, there is a confusing set of new terms to learn. What is the difference between a barrier versus a membrane? Also, what is damp-proofing and is that the same as interior waterproofing?

Is there a better choice to address your specific issue with basement moisture, whether it is seepage or an outright raging leak?

One thing you do know, however: whatever you select, you want it to last. In this post, we discuss important differences between a moisture barrier versus interior waterproofing and the right time to use each.

Damp-Proofing, Vapor Barriers & Moisture Barriers

The best time to discuss protecting your basement space from moisture breaches is before it is even built.

Of course, in most cases this smart conversation doesn’t take place, either because the homeowner doesn’t know (and the contractor doesn’t say) or yours isn’t a new home and you are one in a succession of owners.

The terminology for protective, preventative treatments—often termed “damp-proofing”—can be confusing. Water-resistant membranes, moisture barriers, vapour barriers… they sound quite a bit alike but actually mean different things.

What is most important to know, however, is that none of these products can provide complete protection against basement moisture. If you want full waterproofing protection, you need to find out precisely what type of moisture the product blocks!

Moisture barrier

A water-resistant membrane (also called a moisture barrier) is a sheet of thick plastic that, as its name suggests, blocks moisture from entering through the foundation.

Membranes can be helpful to repel seepage, but they can’t withstand heavy pressure such as that generated by fast leaks and flooding. In this way, to say they are installed for waterproofing is actually inaccurate.

Vapour barrier

A vapour barrier is typically made of polyethylene, a type of plastic sheeting. It is often attached directly to wood or laminate flooring materials to block moisture created by overly humid air.

Unfortunately, this type of barrier is typically effective only until the moisture content in the surrounding air or soil reaches about 75 percent, which makes it ill-equipped for seasonal or storm-generated humidity spikes. And vapour barriers are not the right choice to actively repel water seepage or outright leaks.

Damp-Proofing Versus Interior Waterproofing

In the vast majority of cases, damp-proofing is installed as a preventative, protective measure during new construction or major home renovations. Here, the thought is to provide some type of minimal protection against minor settling or seepage, especially in an unfinished basement space.

In contrast, interior waterproofing is generally recommended as a way to fix an existing issue with moisture seepage or a leak, often with an older home where the basement structure itself is aging and has become compromised in some way.

This is not to say that interior basement waterproofing cannot be done as a preventative approach—and in actuality, this approach is ideal for homeowner peace of mind and for controlling future repair costs.

Interior Waterproofing Versus Exterior Waterproofing

There are two main approaches to basement waterproofing: interior and exterior.

As their names suggest, exterior waterproofing is a treatment applied around the outside of your basement space, while interior waterproofing is applied to the interior of the basement.

Many homeowners do not initially realize there are two different types of treatments—that is, until you start to gather quotes and some quotes are so much pricier than others!

Exterior basement waterproofing

Quotes into the tens of thousands of dollars are typical for exterior basement waterproofing.

This highly invasive treatment is generally only feasible or advisable to do at the same time a new basement is built, since it requires thoroughly displacing the surrounding soil and landscaping, which then creates additional costly repairs.

Interior basement waterproofing

Interior basement waterproofing is a treatment that can be applied to the inside of your basement—walls and flooring—whether your basement is unfinished or finished. If applied to an unfinished basement, the treatment will not prevent you from finishing the basement in the future.

This treatment can be used on its own to treat issues with humidity or slight seepage from micro-cracks. For larger cracks and leaks or standing water, interior waterproofing can be combined with other types of treatments depending on need.

Downspout and gutter repairs or re-routing, window well cleaning and repairs, sump pump backup systems, additional specialized insulation, crack repair, structural supports such as wall joints and braces, ventilation solutions and grading/landscaping can each do their part to provide a comprehensive approach to basement waterproofing.

Which Solution to Choose: Damp-Proofing or Interior Waterproofing

Since no one enjoys spending money to keep moisture or water out of their basement, it can be tempting to just jump at the lowest bid you receive.

But it is important to take a step back and look into the long term—how will the solution you choose today protect you from the unknown in the future and perhaps even impact the resale value of your home?

According to a recent Home Advisor report, prices can range from $600 to $10,590, which is a really wide spread!

What is most important to know here is that whatever you spend now to fix minor issues with humidity or leaks will always be less expensive than what it will cost later if you end up with a major mould and mildew remediation or deep repair job on your hands!

Sometimes it is even possible to control moisture’s impact over the short term by simply installing additional ventilation and/or a dehumidifier to remove airborne moisture and dry out your basement air.

Get in Touch

Are you concerned about an overly humid or damp basement? We can help!

Contact us online or give us a call at 1-866-875-6664.

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