Reducing maintenance with new siding and windows

Q.  You have written that we should take the cedar shakes off before re-siding. Would it be more insulated if the siding is put over the shakes? As a widow, I would like to eliminate maintenance. I would like to replace the windows also so there is no upkeep. Vinyl or aluminum?

A.  Cedar-shake siding is quite irregular and makes things difficult when trying to apply vinyl siding smoothly. You will get more insulation if the shakes are removed, and 1-inch thick rigid extruded polystyrene (XPS) insulation is installed directly over the sheathing.

If your question is whether to have vinyl or aluminum siding put on, the decision is very much up to you and the local market. Vinyl siding represents the bulk of the installations nowadays and, when properly installed by experienced workers, it is a good and long-lasting, maintenance-free siding.

So is aluminum, although it is not as popular as it was decades ago, and you may not find it available in your area. I would urge you to insist on XPS insulation (blue, grey, green or pink) instead of accepting the type of thinner fold-up material some installers will offer you; it is not as effective an insulation, but the dealers like it because it goes up faster.

The windows are also somewhat of a local matter — whichever is most popular in your area: aluminum or vinyl, just make sure that it is a top-quality product. I have worked with clients who had bought lesser-quality vinyl windows, and were beset with cold-air infiltration as the vinyl shrank in cold weather — a tremendous loss of energy. The windows may have looked like they were tight in the store, but they did not perform well once installed.

It is recommended that you get three estimates from reputable contractors, but the most important thing you can do is choose a contractor who has an excellent reputation for quality work, presents you with a clear and detailed contract that stipulates the type of material to be used, a start and finish date, and who follows up quickly on any punch list items (they are almost unavoidable in construction.) Ask for several references of people whose jobs were done recently, one and two years ago (two names for each category), and call them.

Keep in mind that choosing the lowest price is often not the best in the long run.

Do not agree to pay anymore than 10 percent at contract signature with the balance due at satisfactory completion. Anyone who asks you for half or more of the money “to pay for the materials” should arouse your suspicions. Also check with the Better Business Bureau and the consumer protection division of your state’s attorney general to see if there are any unresolved complaints against the contractors you are considering.

Who is responsible for details of building an addition?

Q.  My wife and I are in the process of trying to get an addition to our house. An architect has done the necessary drawings for us to get on the schedule for zoning variances. Assuming the variances are granted, the architect will proceed with the detailed drawings for whatever builder we select.

I must confess that I dread what’s coming: selecting a builder, getting details nailed down, and going through the trauma of the addition. Who is supposed to get the “engineering” details right, the architect or the builder? Things like the right drip edge product you mentioned in a recent column. Or, what to do about the roof? We have an old tongue-and-groove sheathing with three or more layers of shingles; some of the boards are cracked or have missing pieces, and you can see and touch the asphalt product. No ridge vent, no soffit vents, no insulation.  There’s a finished room in the attic (the room is insulated), and it gets hot in the attic in the summer outside the finished room; what is the best approach to improve this?  I recall your column where you suggested 1/4 inch sheathing over the tongue-&-groove, as well as a column recommending “organic” shingles.  And, you prefer hand-nailing. That’s just the roof! Gosh, who is supposed to know all this stuff?

I think my wife’s approach is to just trust the architect and builder, I don’t think I’ll be getting much support there for me sweating over the details with the builder. Any suggestions?  Books?  Moving?  Run away? — I’m too old to join the French Foreign Legion…

A.    The issues you mentioned are all addressed in my book, “About the House with Henri de Marne,” which I hope will be a handy resource as you try to stay on top of the issues you will face. Congratulations on your efforts to understand the process of remodeling even if the work is being done by trusted professionals.

The architect doing the working drawings for your addition is responsible for the engineering, if any is needed. If he or she is not qualified to do the engineering, he or she will retain the services of a structural engineer to handle that phase.

The architect should detail and specify the framing of the addition, the type of metal drip edge, roof covering, insulation, interior finishes, etc. if he or she is paid to do a complete set of working drawings. The architect should also help in the selection of a competent builder.
The builder is responsible for pointing out to the architect any conditions that are unforeseen or not easily handled, or may add much to the cost, etc.

All existing roof covering should be removed. Any damaged sheathing should be repaired. If the existing sheathing is uneven or badly damaged, it should be covered with a layer of half-inch thick CDX plywood.

If you have selected a competent architect and builder, you should stop worrying about these details and anticipate the advantages the new addition will bring you. Building a house or an addition, or doing any remodeling, is a shared project between the client who initiates the process, the architect who designs it and the builder who builds it. Competence of all those involved and trust in their abilities is an important part of the success of the project. Your wife has the sensible approach. Take her out to dinner and bring her flowers, and enjoy life. The French Foreign Legion would be a lot tougher than building an addition.

Concrete chipping from new front steps

Q.    We had new cement steps put in front of our home a few months ago. About two weeks ago, the cement started to chip on the surface. An old friend said the contractor didn’t put a finishing coat on the cement and even if he chips the entire surface and then puts the finish coat on it, it may happen again. He said we should insist on a guarantee from the contractor to protect us if it does happen again. Any help from you as to what to do would be greatly appreciated.

A.    There are several reasons why the concrete steps are chipping, but not putting a finishing coat on it is not one of them — quite the contrary. If the contractor sprinkled cement on the concrete to make it cure faster, it is likely to come off.

If you trust the contractor to be honest and responsible, call him or her back to see the problem. There are ways to remove the unsound topping and to apply a vinyl-reinforced topping if the surface to be treated is not too deep.

Thoro makes Thorocrete which can be reinforced with Acryl-60 for a better bond. Or Top’N Bond, which contains its own binder. can be used. The contractor should be familiar with these products (or equivalent — contractors all have their favorite compounds. Your state probably has a law that makes contractors guarantee their work for one year — that’s pretty standard.

Track down roof leak one step at a time

Q.  I read with interest your article “Roof Ventilation Retrofit”, which I found through the JLC [Journal of Light Construction) Newsletter. As I have a current roofing issue, I Googled for your contact information and found your blog.  I would like to get your independent advice before I talk to a contractor.

The semi-contemporary house has a traditional attic on the eastern part of the house and cathedral ceilings on the west. The original roof (GAF Timberline, 340 lb shingles) was installed in 1981 and performed without any noticeable problems, except for the gradual wear of the shingle grains. In 2005, I had the 24-year old roof replaced as a precaution. It was a clean re-roofing job. The decking was found to be in good condition, except for some loose nails.

Owens Corning 50-year architectural shingles were selected, with added attic ridge vents. (The contractor also installed ridge vent for the cathedral roof.) Ice and water shield were specified at leading edges (6 ft) and 15 lb felt for underlayment for the remaining roof. Chimney flashings were replaced, but not the wall flashings.

Around 2009, during a heavy rain storm, I noticed some water dripping from the window frame in the master bedroom. When I tried to contact the roofing contractor, I found that his numbers were disconnected and that he had moved out of state. I climbed onto the roof to inspect; did not see any obvious problems with shingles or flashings. However, I suspected the problem to be with the flashing at the headwall. This flashing had not been replaced with the re-roofing; the workers simply pushed the new shingles under the original flashing. I caulked the joint from the roof to the vertical wall and for some time the problem seemed to be fixed.

More recently, there was occasionally some water dripping again at the same location at the MBR window frame. On a warm day, I smelled some musty odor in the loft area. (Location 5 on the cross section sketch) Also, the Sheetrock on the head wall at the joint to the roof felt warmer than the rest. I removed a lamp at this wall and traced the smell coming from inside the wall, which could be mildew. I concluded that the head wall flashing needs to be replaced and the headwall opened to investigate. However, before I do this, I would like to have your expert advice and recommendations.

Enclosed is a cross section sketch for insulated roofs and walls and provision for ventilation. All cathedral ceilings have R-30 Fiberglass bat insulation installed between rafters, with a vent channel against the roof deck. Roofs have 2ft overhang and continuous soffit vents. The attic section has wall vents at both ends. Ridge vents were added in 2009 with the re-roofing.

The MBR roof connects to a head wall, which has 4 awning windows. Therefore, even with venting channels in the cathedral ceiling, possible vent air flow through the head wall to the ridge vent is blocked by the awning window framing, except at the center and the two ends of the wall. Some air may find its way through gaps to the ridge. But, this roof section is essentially unvented, did perform OK with the original roof, but is troublesome since the re-roofing.

I enclose a sketch of the concept for installing a new head wall flashing. As a minimum, I expect to remove the siding and Styrofoam and install new underlayment and seal with tape around the windows. I also intend to remove the sheetrock at the inside and remove the insulation to inspect the cavity and remove any mildew which might be present. I wonder if I should seal the area where the roof rafters join with the head wall framing with closed cell foam?, or even fill the head wall, which consists of a number of small cavities, entirely with foam?

Insulation and venting_001Headwall flashing, new concept_001

A.  Thank you for the two sketches, which makes it easier to visualize the situation.

Looking at the cross section of the wall where the leak occurred at the window head in the master bedroom during a heavy rain storm, it is possible that wind-driven rain penetrated the head flashing of the window, if it was not properly installed. Unfortunately, common practice is to install the head flashing over the housewrap or felt paper, when it should be behind it.

More recent leakage under different conditions adds another element to the puzzle. The musty odor you smell on warm days, combined with a warm drywall, tells me that there has been leakage through the ridge vent, which the roofer installed in 2005. If the ridge vent is not externally-baffled (like Shinglevent II), it may have ingested rain and possibly snow over the past eight years, which would drip down the headwall, wet the insulation, negating its R-factor — thus the warm wall in warm weather. The water would be absorbed by the framing at the bottom of the headwall. The musty smell may be a warning of decaying framing.

Your thought that the leakage may be occurring at the joint of the headwall and the cathedral roof of the master bedroom is unlikely, in my opinion. Any leakage taking place in that area would have to run down the entire length of the rafters without wetting the drywall ceiling — an unlikely scenario since you have told me that the vapor retarder of the fiberglass insulation is Kraft paper.

Kraft paper is a relatively ineffective vapor retarder with many joints, which raises the potential for condensation on the sheathing of the cathedral ceiling running down to the joint with the outside wall into which it drips down until stopped by the window headers.

I suggest that you open the area where you smell the musty odor to determine if there is soaking insulation and structural damage that needs immediate attention. I do not think that you need to replace the flashing at the bottom of the headwall unless further investigation points out that there may be a contributing problem there.

As to the cathedral roof ventilation being interrupted by the four windows in the headwall on its way to the ridge vent, there should not be any air flowing through the fiberglass insulation in a wall, as it diminishes its R-factor. The joint of the rafters and the headwall should be tightly sealed. What should have been done by the roofer is to install Air Vent Inc.’s Flash Filter Vent to allow proper venting of cathedral roof, which is not taking place now.

The top ridge vent is also not allowing proper ventilation of the long main roof because it is short-circuited by the soffit vent of the 2-foot overhang on the other side of the peak. Air, like water, seeks its easiest travel paths. The intake at the overhang soffit vent is exhausted through the ridge vent, affecting negatively any ventilation from the soffit vent at the base of the long and relatively shallow roof pitch.

And if the top ridge vent is not externally-baffled, but internally-baffled or not baffled at all, precipitation intrusion is possible — and likely — especially with such short distance, which may encourage weather intrusion through the soffit vent and add to the water that may leak down the headwall.

An externally-baffled ridge vent deflects the wind over the ridge vent, increasing the draw of intake air from the lower soffit vent following the Bernoulli Principle. Internally-baffled vents do not allow this principle to work, as the exhaust feature of the ridge vent is halted. They may lessen the chance of weather penetration, but even that is not absolute.

You had no problem with the original roof without a ridge vent because you had no ridge vent and no air circulation in the headwall. The installation of a non-externally ridge vent changed the dynamics of the functioning of the envelope by allowing airflow — albeit very slow airflow — through the headwall insulation if the joint of the headwall and roof rafters is not effectively sealed.

I also would not apply Styrofoam or any other hydrocarbon rigid insulation in contact with asphalt-impregnated felt paper; the petroleum distillates in the felt will attack the rigid insulation and damage it. Housewrap would be better. Or use polyiso rigid insulation.

If you do any siding removal and repairs, I would suggest that you introduce a rain screen behind the siding, using Benjamin Obdyke’s Home Slicker, which also comes with integral Typar housewrap. Be sure to follow the directions to make sure that the rain screen is properly screened at the top and bottom in order not to allow insect intrusion.

I hope you find this helpful in attacking the problem at its source and finding no need to undo and repair things that should not be needing repairs until proven otherwise. Take it one at a time.

Please let me know what you find as you undertake the repairs, and if my conclusions are correct. It’s always possible to miss something when not on the spot looking at the problem.

Contractors’ ethics go beyond just following code

Q.     I was intrigued by your recent answer to the contractor having condensation problems. As a former contractor, having experienced a similar problem, I agree that the methodology you described may solve the problem. However, you failed to mention three important factors.

Number one: as described, the contractor in question built the cathedral ceilings within applicable building codes, and is therefore not responsible for the problem.  Number two: the applicable building codes have not been correctly updated to take into account the higher thermal efficiency of newer homes. In effect, newer houses do not “breathe”…they are not as drafty as older homes, and therefore there are more problems with condensation, mold and material out-gassing.  Lastly, one wonders if the architectural details required a 6mil vapor barrier, and if so, did the building inspector note the omission during the insulation inspection?

Although it is noble of the contractor to wish to fix the problem, he must weigh the cost of that nobility against the fact that he did nothing wrong. Hopefully the contractor has the financial ability to make the repairs, but the clients in question have the responsibility to split the costs.

A.      You make some interesting points. But as a former general contractor myself and as the founder of an ethics committee in the area where I used to build, renovate and restore some 50 years ago, I disagree with you on several of them.

The fact that a building is built according to code (whether the code is behind times or not) and that the architectural specs do not call for what is essential to obtain a failsafe cathedral ceiling is not a valid excuse for a contractor not to do what he or she should in order to avoid problems. We builders have a responsibility to keep up with the latest technology and to advise clients (and architects who may have omitted an essential component) of the need for any changes to wishes, plans or specifications.

Clients are not builders and do not have the necessary knowledge to have their dreams built without problems; it is our job to make sure there will be none and, if we don’t, we have done something wrong and we must stand behind our work and fix the problem. That’s one way to learn never to make that mistake again.

As an example, in the early 1960s the trend was to install ceramic tiles on tempered Masonite applied over gypsum board, using a new technique: mastic. Bullnose trim made the installation look like a mud tile job. However, after a couple of years, the oil in the Masonite caused the mastic to fail and tiles to fall off. We had done nothing wrong – we had simply followed the trend of the time developed because mud tile setters were hard to find, but homeowners were suffering the consequences. Needless to say, it was our responsibility to replace the tile work at no cost to the clients; an expensive lesson.