Keeping Water out of Your Walls

There have been lots of problems with leaks in walls in the last couple decades. Walls have always leaked but we started noticing as our building methods improved. We began to use sheetrock, and insulate walls and make walls more air tight. When once we used old growth lumber; we have moved to structurally engineered woods for strength and rigidity. All this new stuff in walls absorbs water really well and then all this new woods are delicious stuff to rot and mold.

I figure we started paying more attention to leaking walls and leaking windows when mold began to grow and wood structures began to rot. Now we do not want to go back to drafty houses so we have to figure out how to keep water out of the walls. We will go into the details of destruction by water leaks later but for now…

Let’s quickly cover the purpose of this page.

Our emphasis on this page is to

  • identify leaking problems as quickly as possible and solve them reliably,
  • assess your level of risk for water leaking issues and
  • explore options for prevention.

You might even want to explore options for remodeling that makes you happy but also reduces known vulnerabilities to water entry. It is near axiomatic that water leaks don’t just happen, they are designed and built in right at the point of construction.

We go from this page, to tips on how to identify risk factors with your home, and then we organize a walk around the house after the rain has stopped to see if there are any tell tale drainage problems, to let us know you have a problem.

We then ramp up the conversation to other forms of non destructive testing available to you, until you know exactly what is going on, and what your risk factors are and what you wnat to do..

 What causes water to leak through walls?

The problem is caused by issues with the drainage plane. The drainage plane is the combination of components that resist water and keep water off the sheathing on your walls. The drainage plane can be constructed of many different types of materials, and have slightly different components to support the cladding material- wood or cement siding, brick veneer or stucco types- but the main structures of the drainage plane are there and the purpose is the same. Keep water out of the structure of your home.

If you hear someone talking about a water resistive barrier or WRB they are speaking of the same item- the drainage plane.

Lets examine the components of the drainage plane.

I am going to keep this simple. We are going to use housewrap which you probably have seen on homes under construction in North texas, because this is the standard fare… house wrap is very comparable to building paper and most likely what you have on your home now. Stucco and synthetic stucco  drainage planes should look different. We address stucco issues later.

Now you are stuck with the drainage plane you have, unless you need to tear into the walls of your home. So as we look at how to build a proper drainage plane, our purpose here is to give you perspective on possible differentials between a good drainage plane and what possible hints of issues you might see at your home. This background can help us with assessing our own situations.

There is not much wood siding in Texas these days but the detail can help us. The overlapping joins of the  building paper / housewap allow water that is running down the wall to shed onto the next overap.The overlaps here are  greatly exxagerated for some reason. 4" sidelaps and 6" end laps are more realistic. The furring strips keep the exposed siding away from the building paper to allow proper drainage of the drainage plane and drying and air circulation behind the cladding.  See the text below for more intrigue and details of this simple drawing.

There is not much wood siding in Texas these days but the detail can help us. The overlapping joins of the building paper / housewrap allow water that is running down the wall to shed onto the next overap.The overlaps here are greatly exaggerated for some reason. 4″ side laps and 6″ end laps are more realistic. The furring strips keep the exposed siding away from the building paper to allow proper drainage and drying and air circulation behind the cladding. See the text below for more intrigue and   a description of details of this simple drawing.

The simple drawing above has other key information for us. This metal flashing detail is used to make transitions between stucco to brick, or from a siding material transitioning to a roof line. You might notice a house with a  tudor effect or a barge board running horizontally across the face of the siding.

Look at the metal flashing above. Flashing metal  can create problems at the overlapping pieces of metal. There is a horizontal component to it. This horizontal component can get tipped up at the front edge and hold water rather than shed it off. The metal might be too small or not configured properly for the installation. Flashing metal can have problems with laying properly.

The problem with the flashing sheet metal then starts at the overlapping joints. These joints are under considerable stress because the metal has a coefficient of expansion where the metal gets hot during the day and grows in length and then chills off  and gets shorter in length. If the sealant between these joints, disbond or distort from this sawing action on the sealant; the watertight joint is broken and water running along the  distorted surface of the metal will run off the end of the metal right in the overlap. This water is now behind the drainage plane, unless there is a backing membrane behind the metal flashing material.

There are many  ways for flashing metal to be porous. The joints might not fit right. Poor sealants are used. You will even see where the metal is missing at times. Now metal is not always needed at every transition, but when metal is needed and left out- well you have a propensity for having problems.

All flashing problems in transition areas on walls can be prevented by proper design and proper execution of the design. Properly sized flashing metal.of proper weight, with proper over laps, proper sealants, will not be a problem for you. Problems start with fast and easy methods that add up to mediocrity and more risk for leaks.

Someone here did not understand drainage planes and keeping water out of the house. The original side wall flashing we have to assume failed because a  surface mounted counter flashing has been added over it. This is tied off with sealant to  what would appear to be a Plywood type siding? Sidewall leaks are a problem with the drainage plane. Reliable repairs must solve the problem at the drainage plane.

Someone here did not understand drainage planes and keeping water out of the house. The original side wall flashing we have to assume failed because a surface mounted counter flashing has been added over it. This is tied off with sealant to what would appear to be a Plywood type siding? There is  a chance the new repair might keep water out of the interior but it most likely is not keeping water out of the wood structure. Sidewall leaks are a problem with the drainage plane. Reliable repairs must solve the problem at the drainage plane.

Walls leak around windows.

Windows have been a source of leaks through walls for decades- once upon a time when air flowed in and out more barnlike and structures were not insulated and build of old growth timbers, the water leaked in and dried out in summer. Today, water coming in wets the insulation, engineered wood sheathing is wet, and you get a mold garden and a rotting wood fest. We no longer want our windows leaking. The construction industry has ramped up the effort to keep water out.

I am not going to get involved here in specification for window, we will talk about more details here, where we evaluate the utlity and efficacy of replacing your windows. This is not a trivial matter. They need to be carefully considered. Check out the conversation about replacement windows here.

What can you do right now?

We need to thing about water in walls in a practical manner. No one is going to tear into the siding of any home to fix a water problem until we can verify there is a water leaking problem. And thenwe are going to assess the issue and see if we cnnot solve the problem at the cladding level. If there is a specific defect in the wall we will address that. If the problems accumulate, we will ramp up the size and scope of the solution.

Lets make sure we have a water problem

Get a cup of coffee and wander around your house and enventory any ocurances of tidbits mentioned here to actual conditions on your home. Do you have an upper story? Well you have many more opportunities for water leaks in walls. Look for any transitions in mmaterials on your home. Where doses the siding material change? Where are the side wall  transitions? Where are the window assemblies exposed to driving rain and unprotected by the roof overhang? These are your vulnerable points. We pick up this conversation when we describe our walk of discovery around the house. In fact there are 3 walks fo dicsovery. First a reconoter as described above, and then a walk after a rain, and then a walk around the house, with our eyes out looking for signs of moisture. That journey of discovery starts here.

Every home has a drainage plane by definition. It is the layer intended to shed water away and off the walls. It’s efficacy or mediocrity is related to how well it was built. It determines whether you have water problems or not from the exterior. Good luck with the search.

Do you have a thought or a question? What do you think you will find? Lets us know how it goes.

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *

*

This blog is kept spam free by WP-SpamFree.