The above picture is taken from my parents’ 200 year old farm house on Cape Cod (http://www.saturdayfarm.com/). The original panes have a unique character as gravity has taken hold of the glass over the centuries. My parents say they will never replace them. In many historic districts (like the Montford District here in Asheville) there are rules that limit homeowners from changing or upgrading their windows. For owners of historic homes storm windows might be the best way to keep their houses more thermally efficient.
These storm windows need to be monitored and adjusted throughout the year. The weep holes need to be kept open (not painted shut!) to allow the condensate to exit without damaging the wood. Sometimes the storm windows need to be opened or removed for ventilation depending on the time of the year.
Storm windows are not ideal but in historic homes with regular maintenance and monitoring they are a perfectly good solution.
The picture below is from a house I inspected last week. It was built in 1995. The windows don’t have any historical value. They are cheap single pane windows. In this example, storm windows were installed on the INSIDE of the house in order to keep the house warmer. Let’s look closer:
When the cold air passes through the thin outside window and hits the warm air of the inside storm window CONDENSATION results, but this time INSIDE the house. You can see the damage from the moisture in the picture below. Also if you want to open the window you have to open the storm window first. This is not ideal.
Storm windows are only perfect for historical homes. In other homes storm windows may be cheaper to install but i would rather have 1 new double pane window than 2 storm windows over single pane windows.
In this house, if it can be afforded, all the windows should be replaced and the storm windows permanently removed.
My neighbors Matt and Candra have a classic bungalow in Historic West Asheville and last Summer they were looking to replace their asphalt shingle roof. They preferred the look of a metal roof and they wanted to harvest their rain water with a catchment system (metal roofs are better for rain catchment systems because they don't shed ballast, asphalt and fiberglass fibers into the water tanks like asphalt shingles).
They received several estimates and considered 3 different options:
1) Asphalt Shingle roof
Life Expectancy: About 20 years.
Pros: Reasonably priced. Fairly reliable.
Cons: Not the look they wanted. Not ideal for rain catchment systems.
2) Standing Seam Metal roof.
Life expectancy: 35-40 years!
Pros: Very attractive, with the longest life expectancy. Good for water catchment.
Cons: Twice as expensive as other options!
3) Exposed Fastener Metal roof.
Life expectancy: 10-35 years
Pros: Attractive and affordable. Good for water catchment.
Cons: Un-predictable life expectancy with a mixed reputation depending on which professional you talked to.
Matt kept thinking about the Exposed Fastener Metal Roof (Option #3). This is also called a “fasten down” roof because the screws are fastened right through the metal panels into the roof sheathing. The critics of this roof say that during the freeze/thaw cycle the metal panels move and corrode around the screws where the water can enter. Some of the roofing contractors Matt talked to refused to install them because of call-backs.
Matt was about to give up on the Exposed Fastener roof when he spoke with Asheville Roofing Contractor Francisco Luna who said that the Exposed Fastener Metal Roof was his favorite option for the money but it had to be installed correctly. Francisco's crew pre-drills holes into the crimps of the panels. The crimps are the high points of the panels so if there is corrosion around the screws over time, it is unlikely that water will get under the panels (see diagram below). He said that if the panels are fastened at the crimps instead of the flat areas homeowners can expect an extra 10-20 years of life expectancy.
This was a bold claim but it made sense. This was also consistent with my experience in living in Central America where tin roofs are very common. The metal roofing panels were ALWAYS fastened through the high points, not the troughs. I looked through several installation guides for these products and I discovered that the best practice is to install the screws at the high points just like Francisco claimed. So why are so many roofers fastening the panels in the flat/low areas? The answer is upsetting. It's simply easier and faster to 'screw-down' the panels in the low areas because no pre-drilling is needed. This practice is convenient and profitable for the installers but a huge inconvenience for the homeowner when their roof leaks after 10 years!
After a lot of research, Matt and Candra decided on the Exposed Fastener Metal roof pre-drilled and fastened through the crimps (Installed by Francisco Luna’s crew. See photo below). It looks great and they are looking forward to 25-30 years of a solid roof over their heads.
Note: Metal Roofs get an even longer life expectancy when they are coated with a high quality paint and re-coated every 10 years or so.
Author: Jason Bellamy
Builder Buddy LLC