Ask This Old House

Preparing basement walls for wallboard

Tom helped a homeowner prepare the bare concrete walls in his basement for wallboard. The homeowner wanted to convert his unfinished basement into living space. The first step was to plug the holes in the concrete walls that might let water seep in from outside. To do this, Tom mixed up some hydraulic cement and forced it into the holes. Hydraulic cement expands as it cures, forming a watertight seal. Next, Tom used 2-inch thick foam insulating board to insulate the basement. He applied it to the concrete walls using a special foamboard adhesive. With the foam insulation installed, Tom fastened a wooden "grid" of 1x3 spruce boards over the insulation using masonry "spring spikes." This grid allows wallboard to be fastened with regular drywall screws, and gives an electrician a place to snake wires and install electric boxes for outlets and light switches.

Where to find it?

Tom used hydraulic cement to plug the holes in the concrete foundation:

Quikrete
800-282-5828

Tom used two-inch thick rigid foam insulation on the walls:

Owens Corning Insulation
800-438-7465

Tom used masonry "spring spikes" to attach the 1x3 lumber to the concrete wall.

Manufacturer: Powers Fasteners
SPIKE ® Pre-Expanded Anchor (also called a "spring spike" or "rawl spike")
(914) 235-6300

How to tie four basic knots

Up in the loft, Richard shows Kevin how to tie four simple knots. They are a "square knot," a "slipped square knot," a "fisherman's knot," and a "bowline."

Where to find it?

There are many books available with detailed instructions on tying knots, including:

Handbook of Knots (Expanded Edition)
Author: Des Pawson
DK Publishing, Inc.

What is it?

The guys try to guess the intended purpose of an unusual-looking product.

Where to find it?

Kevin showed several small, battery-powered lights containing magnets that stick to metal surfaces and provide lighting in hard-to-light places.

Striker Hand Tools
Magnetic LED Light
200 Overhill Drive, Suite C
Mooresville, NC 28117
704-658-9332

Repairing storm-damaged trees

Roger and arborist Matt Foti visit an area with trees damaged by a recent ice storm. First, Matt recommended leaving any large trees with damage to a professional tree service. For smaller trees, Matt showed how to repair them using a few simple tools. First, he showed a dogwood with a large structural split near the bottom of the tree. To fix it, Matt used a steel cable to pull the two split "leads" together, which will allow the tree to heal on its own. To firmly hold the split leads together, Matt installed two stainless steel carriage bolts with nuts and washers. Next, Matt and Roger repaired a damaged birch tree with a large branch that had almost completely broken off, causing extensive damage to the tree's bark. To repair the tree, Matt first removed the broken limb. Next, he carefully cut out the damaged bark using a chisel and a mallet, creating a shape that will allow water to run off and avoid rotting out the tree. This technique is called "bark tracing."

Where to find it?

Matt Foti, certified arborist
Matthew R. Foti Landscape & Tree Services
30 Fairbanks Rd
Lexington, MA 02421
781-861-0505