My wife and I bought a lemon of a house a year backIt seems it is incredible hard, and costly, to keep the house cool in the summer and warm in the winterHow can you tell if your home has been insulated? If it has not, is foam insulation the best, or only, option?
You can't calculate it, it must be measuredTypically, people look up values on lineFor hard rubber, wet aluminum, about 0.05For dry surfaces, soft rubber, approaches 1.0Also depends on surface finish of AlSmoother reduces friction, rough increases, especially with soft rubberSelect a soft rubber, clean the aluminum and rubber with alcohol or equivalent to have them clean and dry with no oils, will get good resultsShould be able to readily get 0.3 or betterWe ran trials to verify ours.
Coefficient Of Friction Aluminum
Easiest: First take the covers off the switch/outlet boxes, alot of times you can see into the wall around theseIt will be a small slit around the box so the viewing isn't great but it's a place to startSome of the electrical boxes you might be able to see pretty good, others very littleSecond: You also could take a few pieces of trim off around some windows and doors, you should be able see some or possible create a slightly larger opening to see better but don't go bigger than what the trim will cover back upThis may work on some of the doors/windows, depends on the width of the trim and the framingFor adding insulation to an existing home the easiest is to blow it in from the outsideIn between each stud space they will make an 1-1/2 to 2 round hole and blow it in through the holeThey have small plugs to pop back in to cover the holes when doneIt is not always the best and can be time consuming but it is better than nothingWe are in WI and it is frequently done in the older homesDown the road if you plan on siding the home have them add sytrofoam sheets before putting on the sidingA major heat lost for a home is the atticMake sure you have adequate insulation in the attic; examples; fiberglass batts-you should have two layers, loose fill such as fiberglass(pink/white chunks) or cellulose (gray) you should have at least 12+.
