Tips on Free-Standing Stone Wall
QUESTION: I’d like to build a free-standing stone garden wall in my back yard. Can you give me some tips?
ANSWER: There are two types of stone wall construction: a dry wall (built without mortar) and a wet wall (built with mortar).
With a dry wall, the stones can be quickly restacked if the wall is damaged. This wall needs no footing because it floats with frost heave. The base of the wall should be about 6 inches below grade. Use the largest stones for the base. This avoids the need to lift and replace them.
The mortar in a wet wall keeps the stones in place and makes the wall act like a monolithic structure. Such a wall needs a footing extending below the frost line to protect it from heaving caused by freeze-thaw cycles.
Free-standing walls are usually no more than 4 feet high and should be inclined from the vertical (battered) at a rate of 1/2-inch per foot of height.
Roofing Paper Gives Added Protection
Q: Recently, I was approached by a homeowner who was concerned that his roof did not appear to have roofing paper between the asphalt roof shingles and the roof deck. He was told by the contractor that the shingles were designed not to require roofing paper between the shingles and the roof deck.
Despite assurances by the contractor, the homeowner remains skeptical that any such shingle exists. I would appreciate your comments.
A: The roofing industry educational institute said they knew of no shingle as you described it. The type of shingle does not determine whether roofing paper is used, since the paper is supposed to provide additional protection against water penetration. Also, if a few shingles rip off in a windstorm, the paper is supposed to protect the roof deck. Most building codes require roofing paper.
Two building industry trade groups disagree on the subject. The National Assn. of Home Builders says it is not necessary to use the paper, and the Asphalt Roofing Manufacturer’s Assn. says it is necessary.
According to NAHB, when many of the shingle companies closed their organic shingle plants and started making inorganic-based (fiberglass) shingles, they stopped making their 15-pound felt (roofing paper) and started making fiberglass-based roofing paper. Contractors said the new paper wrinkled if it got rained on or if it was left in the sun too long.
The Asphalt Roofing Manufacturer’s Assn. says roofing paper is necessary because it has a bearing on fire resistance. Shingles are fire-rated as a component of a roof assembly that includes roofing paper and decking material. It also says the roofing paper helps shield the deck from the wind-driven rain.
Deteriorating Bricks Must Be Replaced
Q: The exterior brick of our home is porous and is starting to crumble. We had it tuck pointed and sprayed with a transparent water repellent. This has helped very little. Would painting the bricks with a vinyl or lucite paint stop the crumbling? Our home is 26 years old.
A: Unfortunately, the only solution is to replace the deteriorated bricks. Water penetrates through cracks in mortar joints. The water freezes and thaws, causing the bricks to spall.
Once the bricks spall, you cannot reverse the condition. You can only reduce further spalling by sealing cracks or open mortar joints.
Sealing the brick face with a clear, penetrating sealant is not recommended by the Brick Institute of America. It can cause more harm than good by trapping moisture that was present in the brick. This moisture freezes and causes the bricks to spall.
Painting the bricks is a stop-gap measure. The paint can act as an adhesive, keeping the crumbled pieces together. When the adhesive properties of the paint reach their life cycle, and the paint peels off, the crumbled pieces will peel off with it.
