Most Older Homes Have Wall Studs That Measure Only Four Inches Or Less In The Walls In Depth

Most older homes have wall studs that measure only four inches or less in the walls in depth. In many cases the studs are also two inches thick. New wall studs measure one and five eighths inches wide and three and a half inches deep. These size studs will nicely accommodate three and a half insulation or R13 energy value but R19 or six inch thick insulation is much more desirable and in fact is required by the US energy code today in all new homes.

If you are renovating an older home, future energy costs are of a prime concern. Leaky windows and doors, no insulation in the walls and inefficient furnaces are just a few of the things that need to be upgraded. Insulation can be added on the interior or exterior of the home. If you are re-siding the house, adding a one inch insulation board behind the siding can increase the insulation value of the wall dramatically. If the exterior is stone or brick perhaps, then the insulation must be added to the interior.

There is a way to use six inch insulation but it requires a great deal of extra wood detail work. By adding depth to the studs you can then use six inch insulation batts. Assuming the room has been stripped to the studs, install all your mechanical items such as electric wiring and plumbing. Leave wire drops at each outlet box locations but do not install the boxes as yet. The same with the plumbing rough-ins. Leave extra long nipples at stub outs that will accommodate a six inch thick wall even though it is now only four inches deep.

Next on the list of work is to rip some two inch by two and a half inch wood furring strips in long lengths. If your studs are eight feet high, make the rips eight feet long and so on. Make as many rips as there are studs in the room plus enough extras to ring the room in footage twice. You first install a complete ring of the ripped materials around the room at the floor and ceiling to pack out, or extend, the top and bottom plates two and a half inches. Then using more rips, pack out each stud in the room by nailing on a strip to each stud. Door and window jambs must also be packed out in the same manner using the furring strips. Once done, you now have wall cavities that are six and one half inches deep. Install all your electric boxes setting them to the face of the new wall studs plus the drywall thickness.

Six inch insulation will now fit nicely and leaves a half inch dead air space at the outside wall. Lap the insulation paper onto the stud faces to provide the best vapor barrier you can get. If barrier is missing in some areas use a small piece of plastic sheet as a substitute.

Once your drywall is installed in the conventional manner, You will of course notice that the door and window jambs do not reach flush with the face of the drywall which allows you to install trims. You must at each window, door, sill, apron or other trimmed items, install a jamb filler to extend the jambs out flush with the drywall surface. Using a portable table saw and number two or tấm lấy sáng polycarbonate better pine boards, cut a piece to length and stand it in it's place. Using a good sharp pencil, scribe a line flush with the drywall along the backside of the pine board. You will find in old homes that the jambs are seldom square and vary from top to bottom in width somewhat.

By scribing the line, your pine extension jamb will be perfectly flush each time. If you pre-measure the extensions before you purchase the pine and find they are in the 2-3 inch wide area, buying wider widths of boards may enable to you to get two extensions out of one piece of wood. Be careful though as wider boards cost a great deal more than narrow ones. A wider number one grade board can be very expensive. By being choosy, when selecting the number two boards, avoid as many knots as possible and it may be cheaper to actually purchase more number two boards than better grade ones.

Install new or replace your finish trims and the only evidence of the thicker walls will be the deeper window wells and door jambs. Most people won't even notice that the room is five inches smaller. Your pocketbook will notice next winter when your fuel bill is much lower. The added insulation will make the energy consumption for both the heating and cooling systems drop dramatically making your house more "green" and putting some extra dollars in your pocket.

Pete Ackerson
Your Friendly Building Inspector
website to Install Six Inch Wall Insulation in an Older Home