More importantly, can you renovate a house that’s disaster resistant at a cost normal humans can afford? A good friend of mine sent me a link on designing a fireproof home, or making an existing home much more resistant to disasters like the wildfires in California. I’ve included a link at the end of this post.
The article was written by Murray Milne, a professor of architecture at UCLA. After carefully reading the piece, it occurred to me that many of his design points have value in protecting against other natural disasters. When you analyze how nature is going to attack your home sweet home, most of the scenarios break down into three categories, fire, water and wind. With a little extra thought, it’s possible to take some of Mr. Milne’s fireproofing ideas, and extend them to deal with other disasters.
Protecting against water, both floods and precipitation. Floods are more about the site, but precipitation is something where design can help. There’s a lot more detail here, but I’m going to save dealing with water for a separate post.
Many of the ways you would deal with fire, are also valuable in dealing with wind. So let’s go down the list and see some of Mr Milne’s guidelines can be easily and cheaply extended to deal with disasters other than fire
Site Layout. Fire resistant buffer space around the house is the first line of defense. This also protects against falling trees. At least have enough distance so that the heavy part of the tree can’t fall on any part of the structure. Having driveways that allow fire trucks to get close easily is a good idea. If you live in a rural area, remember that you have to pump that septic tank on a regular basis. Design your drive to do double duty. I wonder if fire fighters have something in common with burglars? Visibility is important to both, even though they have different objectives. Whether we’re talking about a rural wildfire or an urban fire that’s spreading rapidly, the first responders are going to have to make a quick assessment of what properties can be saved, and which to let go. If you make life hard for them with poor visibility and access, and extra fuel nearby, they might just move on to a house they know they can save.
Ember resistant materials. The UCLA article mentions using metal of tile for roofs, and cement or other fireproof materials for exterior walls. I’ve mentioned in previous posts the importance of an airtight envelope for energy efficiency and comfort. It’s also important in keeping out both fire and water. Interior insulation like rock wool is much more fire resistant that fiberglass, and also will not absorb moisture. It’s a little more expensive, but is has a higher R-value, and is a lot cheaper than repairing fire or water damage.
Windows are a weak link. Mr Milne makes the valid point that radiant heat can cause interior materials to reach flash point before the windows break. Windows are also the weak link in any storm that generates high winds and flying debris. On the east coast, we have hurricane shutters. The better ones are made of corrugated metal and roll down to cover windows. They are really effective against flying debris, so they should be ideal to protect against wind born embers.
- Doors, especially garage doors are another weak link. And don’t forget doors that access basements or crawl spaces. Metal jambs and a layer of metal or some fireproof material in the door can radically extend the time it takes to burn through. Tight fit is crucial here.
Holes in the envelope. Already mentioned in other posts, minimize openings in the exterior envelope. Where openings are required, use tight metal screens to protect against flying embers as well as wind driven rain. Screens that cover both ends of roof ventilation are critical. Keep hot stuff from getting under the metal, and at the same time allow water to flow through. An additional benefit of screens is that they keep out bugs. Vents can have dampers that keep air flowing in the correct direction.
There is another area that needs some discussion, water management. This is an area where you can do a little or a lot. The simplest solution is to use rain barrels. In addition to managing water for the garden, and keeping the water bill under control, they are also a source of water in the event of fire. In Australia, it’s rare to find a rural or outback house without some kind of water tank. They are basically for managing fresh water, with the bonus of being available for protection against bushfires. Aussie bushfires are similar to American wildfires in that they are fast moving and extremely hot. The fast moving part is good in that you only have to protect the property for a short period of time. Every home, whether rural or urban is a unique situation. In urban or suburban America, it’s more likely you will need protection from a neighbor’s house fire. In either case, ten minutes could easily make a huge difference.
So how much water to store, and how you can get it to perform multiple jobs, needs some careful thought and evaluation. How far you can stretch the budget, and what is the long term value? Big tanks get expensive, then again, it could mean the difference between seeing your life destroyed by fire or surviving in relatively good shape. Not safe in the event of a nuclear holocaust, but fairly effective against most things mother nature can throw at you.