How must we pay attention to thermal expansion when constructing siding on a house? What is a common design technique that is used in modern siding to allow for thermal expansion? Please provide us with a photo as well. A 4.00 m2 wall consists of a slab of wood (oak) 3.20 cm thick, a 10.5 cm wad of wool insulation and then another slab of wood, 2.37 cm thick. What is the total conduction rate through this wall if the temperature difference between inside and outside is 19.5 K? I started by looking at the variables given to me and looked up the conductivity rates for wood and wool. I also had to convert the variables form centimeters to meters since meters are used in the equation to find the total conduction rate. The problem looked really complicated once all of the variables were substituted into the equation. Does anyone have tips on how to clean it up, or break it down into smaller steps? I think when there's a lot of variables it's hard to keep track of them. Also, would combining the two conductivities of the two slabs of wool affect the answer? I thought this would make the problem easier, but I could have messed up at this part