Water Intrusion into Wood Frame Walls

At first glance, you may think this does not apply to you, or, you may wonder what an article such as this has to do with windows. This is after all a hurricane impact windows blog, right? Well, it has everything to do with windows, as you will see, and the chances are very good it’s relative to the home you live in.

On many low rise condo buildings, and most homes, the exterior walls to the second or third floors are constructed using wood framing. I use to be a big fan of wood framing as it offers much better insulation value. The problem with wood framing in exterior walls is the potential for water intrusion into the walls – a HUGE problem for your home or building. One of the big things our company constantly deals with in Florida, is water intrusion into a building, and it can come in buckets (pun intended!) through the roof, exterior wall finishes (such as stucco, siding, etc.) and windows (now you see the connection!).

It is VERY difficult for the average home owner to notice the ‘signs’ of water intrusion until it is too late. Usually, by the time the ‘signs’ appear, there is extensive damage. In a wood frame wall, every component that makes up the inside of the wall – wood wall studs, wood plywood sheathing, sheetrock, insulation – are all absorbent materials, so they HOLD the moisture in place thereby accelerating deterioration. Moisture in building materials can quickly destroy the structural integrity and nurture mold and insect infestation. Repairs for a home start at several thou$ands and can go into tens-of-thousands in very quickly. If you are a condo association, let me put it this way: one of our clients is a very small COA in Boca – 42 units – that we are making these exact repairs (framing, windows, roof, etc.). This association’s cost so far is over $200,000.00 and we are not close to being finished. We have only made absolutely necessary repairs; of the units we have made repairs to, the cost has ranged from $7,000 to $20,000 per condo unit. As I said, it’s hard to find the telltale ‘signs’ for anyone, but for a COA, its especially problematic because the association is having to rely on uninformed condo owners, and worse, renters, to tell you they have a problem.

Window Leak
WINDOWS: Notorious for leaking after a reasonably short period of time from being ‘new’ are horizontal sliding windows (“HS”); but any and all windows are likely to leak eventually. Most windows require screws in the bottom of the frame to attach it to the building. The screw attachment, and the joints in the bottom portion of the window frame create passageways that eventually allow water intrusion into the walls. The way HS windows are designed, they are especially prone to leakage. All HS windows have a “reservoir” in the bottom track – it is the part of the frame that holds the sliding portion of the window in place, allowing it to slide back and forth. By design, the track lets water in, and then it drains out thru “weep holes” on the outside of the window. In a heavy rain, this reservoir can stay full of water for an extended period of time. If the screws in the bottom of the frame were not properly installed (not exaggerating, probably over 90% are NOT installed correctly), or if there is the slightest crack in the joints of the frame, water is going into your walls.

It is easy to check if the bottom track was installed properly. Remove the sliding window, then take out the ‘frame sill track’ that is located under the sliding window and runs the entire length of the frame. The fasteners/screws will then be exposed. Take out one or two and see if the holes were back-caulked. If not, fix it yourself. Remove all the screws in the bottom track; fill the cavity with a quality caulk or seam sealer, then put the screws back in. When the screw is 1/8” out from being secured to the frame, add a dab of caulk under the head for good measure, and finish tightening. It is also a good idea to add some sealer to the corners and any seams in the frame you can detect. Then wipe off all excess and put the window back together again.

This one can be hard for the layman to understand – how water infiltration can occur thru the outside skin of the building envelope. But it happens much more often than you realize. One first has to understand that water is VERY intrusive. And the possible points of intrusion are many! Any protrusion along the stucco wall that impeds water run-off is a prime candidate to eventually create an opening for water intrusion: windows (if they stick out), window sills, stucco bands, ornamental designs, etc., are all candidates. And barely visible cracks in the stucco that can be created from building settlement are obviously points for water to seep in. Once the water gets behind the stucco, it makes contact with the building substrate (usually plywood) – as I said these are absorbent materials, like a sponge, and when they get wet they wick the moisture throughout (drywall can wick water up to 30”).

Roof Leak – Wall Damage
This one I am not going to elaborate on because we all kind of get it. But if you realized the ENDLESS number of weak spots in a roof where water can get in, it would make you wonder how we so successfully keep it out. Missing tiles or shingles, valley and wall flashing, drip edges, torn underlayment, etc., are just a few. And again, if water gets into that wood wall, we know we will have a problem.

For most of these telltale signs to show up, please keep in mind that there has to be enough excess water inside your wall that it is wicking out to the dry side (or in some extreme cases, running out). These signs can be water stains on the ceiling, sheetrock tape joints that have separated, the top of the baseboard has separated from the sheetrock leaving a crack, the sheetrock side ‘return’ to the windows at the bottom is separating from the window sill or there is light mold on the sheetrock in this area, hairline cracks in the outside stucco (often times near an impediment to water runoff such as window sills, stucco bands and other protruding trim).

I recently had one customer who had none of these signs, but by simple good fortune they found they had a serious problem – they inadvertently rubbed their hand against the wall and their wall was so wet inside that that the paint pealed right off the sheetrock. They cut a hole in the sheetrock and found the wall studs to be rotted half way thru. In another project we were working on, I have seen an entire wall, from corner to corner, not have one single wall stud that was not COMPLETELY rotted through. The only thing holding up the roof was the stucco and the side adjoining wall.

If you think you may have water intrusion into your wall, call someone. If you are a condo owner, call your association’s property manager or someone on the board. If you’re a homeowner, call a contractor who specializes in this kind of work. Get someone who is an expert. A lot of contractors will say they can fix water intrusion problems, but unless they have dealt with solving these problems for years, they do not know all the intricacies involved. And as always, with any contractor you hire, call their references.

Source: http://blog.arttofimpactwindows.com/2011/06/water-intrusion-into-wood-frame-walls/