INSULATING WALLS OF OLD FARM HOUSE

QUESTION FROM NATHAN OF OAKFIELD, WI:

I have an old farm house with masonite siding and very little insulation.  I have been looking for a contractor to put a spray foam insulation in my walls. Is it possible to do this in a closed up wall?  I have been getting mixed answers.  I do not have the money to add new siding at this time -- this is why we are looking.  Thanks
 

ANSWER FROM THE INSULATION DOCTOR:
Hello Nathan,  It is possible to blow foam into a closed cavity.  The problem is that you have to allow for an excessive amount of expansion as it dries.  For this reason, you will need a very experienced contractor.  Spray-in foam has the highest R-value obtainable, but it is also the most costly by far to have installed.  I would recommend that you check into the cost of having cellulose insulation blown-in the walls.  You would still be able to achieve a very high R-value at a much lower cost.  
 Hope this helps you out.

Bruce Jones
The Insulation Doctor