Q Our daughter travels from state to state, working for festivals. Although she uses our address for billing purposes, she hasn't lived here for 14 years. Do we count her as a member of our household on the census form?

A If she has no other usual address, then, yes, count her as a member of your household, said Barbara Ronnigen, demographer for Minnesota Census 2010. However, if she has another address where she lives most of the time, then she should answer the census form she receives there.

Shield against ice dams Q I had my roof reshingled last summer. The roofer said he would add a special layer under the shingles so I don't have to worry about ice dams. So why did I have ice dams this winter? Should I contact the roofer?

A If you are not satisfied with your roof or have questions, contact the roofing contractor.

However, it's my guess that the contractor was referring to a strip of water-resistant material (usually a rubber-like membrane) often called by the trade name Ice and Water Shield. The State Building Code requires that it be placed under the shingles along the roof's edge and in valleys to minimize ice-dam leakage.

This membrane works well, often providing protection 4 to 6 feet up a roof. However, if ice dams get large enough, water can reach higher than that and leak into the house. That's particularly true in valleys (areas where two roof sections meet).

This special layer doesn't prevent ice dams, but it does minimize ice-dam damage.

When reroofing, owners of homes that are prone to ice dams might want two courses of this protective underlayment placed around the house and all the way up the valleys for extra protection.

To prevent ice-dam development, you have to work inside the roof deck, in the attic areas of your house. It takes three steps, in this order:

• Seal the attic from the house by finding and caulking or closing all the gaps, holes and spaces that let warm indoor air escape into the attic.

• Add insulation to attic spaces.

• Be sure you have enough, but not too much, ventilation.

You don't want to skip a step, say just add insulation and ventilation, because most insulation does not stop air movement. That means the extra ventilation will end up pulling more warm air into the attic, exacerbating the ice-dam problem.

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