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Q: We're doing an extensive remodel, and our builder is recommending cvpc water pipe. This PVC relative is probably noxious to make, but so is copper pipe, and copper leeches into acidic water. We're told cvpc is very stable, heat effecient (loses less heat from water heater to use), etc. In the long run what are the tradeoffs and comparisons with copper?

A: (Leon) My best recommendation is to contact the manufacturers directly and get case reports to do a comparison between PVC and copper.

Q: I want to use ironwood shingles in an alpine environment, but do not know of even a single example of this having been done before. Do you know of any examples of ironwood shingles being used in alpine (non-humid) environments? I can't use it unless I see that it handles this environment- any help appreciated.

A: (Leon) I 'm not aware of any ironwood shingles that have been used in an alpine environment. I was able to contact a source who works with the product and here's his answer: "Greetings, it's interesting to note all of the inquires I've had with this project in NZ. We have been selling and installing this product for almost 20 years and do not have an exact example of every condition on the planet. With the same specific gravity as aluminum you'd think that that alone would be enough to satisfy even the most critical builders/architects. There are different thickness' to stop any curling etc.

Q: Do you know of any examples of people preserving conventional "cracker boxes" with natural materials, such as earthbags, rammed earth or adobe?

A: (Kelly) I don't know of any examples of people retrofitting cracker boxes with rammed earth, adobe, or sand bags, but somebody has probably tried some of this. There would be lot of finicky details to work out (such as details around doors and windows)...I would rather start from scratch myself.

Q: I would much rather start from scratch as well... but, perhaps the bigger concern on a grander scale is not necessarily all of the homes to come that have yet to be built - but the homes that currently exist (there are more of them), many of which have been standing for quite some time (my home 100 years for example), and it is not their fault that efficiency has improved and technology has left them behind, so maybe it wouldn't be right to scrap them and start over, and we can't all go off to the wilderness to set up our dream homes in pristine valleys and remote mountain tops - because if we did they wouldn't be pristine or remote any more... So I guess where I am coming from is how can I best honor this wonderful building which has served the test of time and now serves as my home, and at the same time honor this amazing planet which provided the materials from which the home was built so long ago and heated for so many years in a time when concern over such things as having less of an impact on the planet is most beneficial for all concerned?

A: (Kelly) I didn't want to imply that retrofitting and upgrading existing housing was not a noble effort...it certainly is! It is just not so easily done, or at least each particular dwelling needs to be considered independently as to how best to approach it. For instance, your idea of using earthbags, adobe, or rammed earth in this regard, presents the problem of how to put these thermal mass materials inside an existing dwelling, where they ideally belong. Strawbales, which are best put outside to insulate the walls, need to be put on a substantial foundation and protected from the weather, so they also present challenges. With careful planning, these things can be done, but there is no obvious formula for every house.

Q: There are many homes that currently exist which have been standing for quite some time (my home 100 years for example), and it is not their fault that efficiency has improved and technology has left them behind, so maybe it wouldn't be right to scrape them and start over, and we can't all go off to the wilderness to set up our dream homes in pristine valleys and remote mountain tops - because if we did they wouldn't be pristine or remote any more... So I guess where I am coming from is how can I best honor this wonderful building which has served the test of time and now serves as my home, and at the same time honor this amazing planet which provided the materials from which the home was built so long ago and heated for so many years in a time when concern over such things as having less of an impact on the planet is most beneficial for all concerned?

A: (Kelly) Retrofitting and upgrading an existing housing is just not easily done, or at least each particular dwelling needs to be considered independently as to how best to approach it. For instance, using earthbags, adobe, or cob in this regard, presents the problem of how to put these thermal mass materials inside an exiting dwelling, where they ideally belong. Strawbales, which are best put outside to insulate the walls, need to be put on a substantial foundation and protected from the weather, so they also present challenges. With careful planning, these things can be done, but there is no obvious formula for every house.

C: Michael Reynolds would have us wrap a cracker box in tires. The only problem is most urban settings don't have enough room for what Michael proposes. The stuff that Nadir Khalili does however has the same effect on tempering against the outside elements only it is much thinner (I have never been in a rammed earth building so I cannot comment, but I would imagine it to be similar). So my only concern was tying in the two modalities - the heavy earthen outer wall and the existing building - mainly the foundation, and then how do you sell that to a local building code official? The actual building of the walls would be just like laying brick or adobe (only bigger). Tie the walls into the existing structure as in laying brick, with railroad ties for lintels, and a concrete cap to fasten a sill plate on to for extending the existing roof out a bit. Sealing the existing building side of the wall would depend on the wall material, but generally it could be filled with R7/inch expanding foam like retrofitting empty walls, or perhaps papercrete. Now there is this wonderfully thick outer wall buffering against the outside changes so anything that happens inside won't just go away (assuming we've remembered to take the attic as close to R60 as possible). Most cracker boxes have crawl spaces and some have basements these can become the heat sink later. First lets get the building to stop using so much energy just sitting there - the common formula for any building. If it already exists, what parts of it can be used to environmental advantage, and what needs some tweaking? So again foundation concerns and then selling it to a building code official.

Q: I am a citizen of India and I have built my house two years back in the south part of India in Chennai city. After 1.5 years of completion I have observed many air cracks formed (like a world map)on both the exterior and interior faces of the walls. As I have already spent a lot of money on building the house, now I look for a good, cheap and permanent solution to fill the aircracks without visibility and make my house to be in good shape. Thank you in advance for your best suggestion.

A: (Kelly) It sounds to me like the plaster work was not completed properly; either the original materials were not mixed right, or they were applied improperly. Obviously the plaster has shrunk, leaving the network of cracks. I have seen this happen when a plaster is applied too thickly, or when the plaster has too much lime in it. The solution is likely to re-apply a final coat of plaster over what exists, but the fact that it has been painted could present some difficulties, depending on whether the new plaster will stick or not. I recommend getting the advice of a local specialist in this work.

Q: It would be interesting in hearing your views in building homes resistant to flooding. etc! But I would think your comment would be to avoid building anywhere near areas liable to flooding..lol

A: (Kelly) You are absolutely right that I would advise against building in areas subject to massive flooding, especially along the coast where hurricanes are frequent. If one must build there, then I would design something using materials that would not be damaged by water and in such a way that when water does arrive the building will stand. Earthbags have this potential, as does other masonry materials such as stone, or concrete.

Q: I just bought a house in a flood prone area. The walls are made of bricks and cement.  The foundation has sunk slightly due to poor piling. The interior walls have recently been painted but has turned yellow and brownish at the bottom. Some of the stains are due to past floods.  On top of that, when I scraped off the paint from the walls, it peels off easily and the walls are slightly moist. If I have it repainted, the same problem will crop up. Can you kindly advised me on what can be done?

A: (Kelly) From your description, I would say that your main problem is that with the inadequate foundation, you have moisture wicking up into the masonry wall from the ground. No amount of prep work on the wall prior to painting will solve this problem. I'm not sure what you can do about the moisture, other than digging a French drain around the base of the foundation on the outside and try to direct all moisture away from the wall. You might consider scraping off all of the paint and leaving the wall natural brick. Good luck with this very difficult problem to fix!

Q: We have a brick house on a slight slope. Occasionally rain water collects outside one of the walls and seeps up under the bathroom floor creating a damp area. Should we put a concrete apron around the house or do you suggest something porous? What is your advice?

A: (Kelly) I suggest that you carefully create a French drain around that side of your house that is giving you problems. This means digging a trench, perhaps 1 foot deep and 1 foot wide, laying perferated drain pipe in it, and then surround this with gravel up to the ground level. The pipe is laid in such a way that is will drain any collected water to some "daylight" away from the house.

Q: The cabin is on wood skids...what kind of foundation should we consider/attempt? Want to save the cabin. Ground is wet and muddy year round. 75yds away from riverfront in Washington State.

A: (Kelly) There are several approaches to putting the cabin on a firmer foundation, ranging from a traditional continuous concrete foundation to raising it up on piers. If the skids aren't rotten, you might be able to simply jack the whole cabin up off the ground while you create a substantial rubble trench foundation using local stones underneath where the skids are, and then lowering the cabin back down. This could be done with little cost and could be quite effective.

Q: I live in Northern Vermont and I'm looking to start ASAP cutting down some trees to construct an Adirondack type lean-to. My question is considering the fact that I mostly will be working alone. I'm concerned that the time allowed for me to do most of the cutting peeling and stacking of the logs will cause them to rot. I will be using pine and have read a crazy amount of books that talk about when to cut etc etc. My lean-to will be about 12 x 12. Is there something on the market that's reasonably priced that I can coat my logs with while I continue to cut, peel, stack , inventory the logs before I actually build next year?

Why next year? I again read many things about green wood or seasoned wood and for me I think, or lets say feel, that if I let the logs dry for a year after they were hopefully stacked properly this will help reduce the amount of moisture in the logs which can help me maneuver the logs easier due to the weight reduction, if I'm in fact totally alone while doing this dream of mine. Do I sound confused or mis-informed here? Is using green wood while building the way to go? I would really like to have this structure last as long as possible, but again my help let's say is far and few. I don't want to waste time and efforts just to have this project fall to the wayside due to rotting wood that could have been prevented. I've seen a product called Penetreat, but this also requires another product to be purchased to coat the logs with after you use this. My location is pretty much in the middle of nowhere and I'm really looking for convenience. Time is really not on my side, but being a stay at home father as well as a husband make my weekends limited and when I do get out I want to work efficiently. If I didn't read more up on this I would have just cut, peeled and stacked the wood, without treating the wood thinking that protecting the logs from the elements with a tarp was good enough.

A (Kelly): I suggest that you cut, peel, and stack your logs as you planned. The best way to keep them from rotting is to let them dry out and keep them off the ground with plenty of air circulation around them. It is usually easier to peel the logs when they are still green, since the bark will separate more easily. Pine is a fairly soft wood, which may be more suseptable to rotting than fir perhaps, but still it should not rot if kept dry. I would only tarp it once it has had a chance to dry out completely, which may take a whole year, dependiong on the climate. You can expect the logs to split (or check) lengthwise some, but this does not affect their strength or usefullness in building. It is much better to work with dry wood, because it will have shrunk and should not warp any more after assembly. Once you have built your cabin, then you could give it a coat or two of boiled linseed oil to help preserve the wood. A design that has a good overhanging roof will help keep the logs from rotting over time.

Q: We purchased a doublewide mobile home that is on piers at 4' high. Our lender required a block foundation. Well, the guy put in a footer and then 4' of block and left about 2" between the top block and the bottom of the home. We would like to apply a cementitious polymer overlay, and then we would stamp it with a cement stamp. After it would dry, we would stain the cement to resemble real stone. Not sure if this is a rock question, but you may have come across something like this: Would the fact that the home is on piers affect how we apply the cement? Would the piers cause cracking later? Is there anything we can do first to help prevent cracking?

A (Kelly): I think what you have in mind should work. One way to minimize cracking where the materials may be different would be to attach a stucco netting over the entire area before you apply the plaster.

Q: We're 2 sick retired seniors not able to paint our 36 yr. old split level cedar shake house. Painting again is too expensive as it would have to be painted again in 5 yrs. or so. If we have the house vinyl sided, should the old cedar shakes be removed and replaced with Tyvek and R4 insulation or should they vinyl side over the old cedar shakes. Some of the cedar shakes are wet and blistering, but only in a few places.

A (Kelly): If the cedar shakes are in relatively good condition you might consider blasting the old paint off with a pressure steamer or something and leaving the wood to weather naturally. Cedar will last a good long time, and the fact that they have been painted means that may not have weathered much. Then you wouldn't have to paint them regularly. Those that are blistered or not in good shape could be replaced. If you want to put vinyl over the old shakes they should be absolutley dry, or you can do the Tyvec and insulation route.

Q: I've been looking at a house built in 1888 with a stacked rock foundation. It has a relatively small sag in one section where a small door was put in to shovel in the coal, I imagine. This section has been supporting the house with only a couple of 2X10's. The frame of the house is triple layer thick brick. Do you have any suggestions on how to fix this without making it worse? The sagging is very visible on the exterior of the house and also affects one window

A (Kelly): Repairing foundations is a very tricky business, because the process of repair can have many repercussions on the rest of the structure. Without seeing the exact situation, it is hard to suggest a remedy. There are ways to temporarily jack up the house while you repair the foundation, either by replacing the original stones, or by puting in an adequate lintel across the doorway. I suggest that you seek the advice of a local builder who can access the situation first hand and make suggestions.

Q: I have a one story house in front of the beach in Greece, with hot summers and cold winters with very high humidity. All the beach front houses like mine experience the same problem more or less: The exterior and interior stucco (over brick or concrete) is getting wet and falls out over time due to the humidity from the ocean and the water levels below. Is there a material you would suggest that can prevent this problem? If stucco is an answer, should it be mixed with appropriate materials and in what proportions?

A: (Kelly) This sounds like a difficult problem to deal with. Even if you somehow render the stucco waterproof, there is always the potential that moisture can get behind it and weaken the bonding with the materials supporting it. Obviously, a stucco netting would help keep small pieces from breaking off. And it might be that a more water-proof stucco that uses a high ratio of Portland cement or has liquid latex added might help. It might take some experimenting over time to find the best solution. Maybe just leaving the brickwork exposed would be even better.

Q: Thank you very much for your time and your suggestions which I find very logical and will apply. I just wanted to also ask your opinion about the option of using Styrofoam materials. The idea is to remove the existing stucco, up to the brick surface, then fasten this one inch Styrofoam material by DOW, and then apply a thin coat of stucco. I checked with DOW Company and they suggest that their Styrofoam material can be used in high humidity environments and is considered moisture resistant but they do not provide any warranty other than the thermal warranty on the R value of the foam.

A: I would say that the use of the stuccoed styrofoam might work quite well in your circumstance, since it not only would provide a moisture barrier and a different substrate for the stucco, but it would also provide a layer of exterior insulation which would make the interior masonry act as a thermal mass. Your house would be more stable in temperature, and easier to keep comfortable over all of the seasons.

Q: I live on the Rockaway Peninsula in Queens, NYC which is a long narrow peninsula with the Atlantic on one side and Jamaica Bay on the other. The average altitude is "sea level" and we do get hit often by large storms, high winds, high tides and flooding. What would be the best natural material to use that would be practical in such an area with sandy soil?

A: Certainly building with materials that are not adversely impacted by wind and rain or flooding would be important. So any sort of masonry material, such as stone, brick, or concrete would work. A more alternative approach would be the use of earthbags, which can be filled with gravel (especially on the lower courses). Earthbags can also be fashioned into domes which are especially resistant to winds. With the advance of global warming and likely rise of sea level, you might want to raise the entire house up on piers...

Q: Hello we recently bought a home in middle Tennesse. The home is only 18 months old and has a circular peagravel and concrete driveway, our problem is it is cracking all over, some cracks all the way though. Our question is what may be causing this and is there any way to repair it. I've tried caulk but the cracks just open up again.

A: Once concrete starts to crack there is really nothing that will completely repair this. You can fill any voids with various commercial products that are designed for concrete repair, but this will not keep the crack from enlarging. The only total repair is to either remove the concrete completely and start over again with proper reinforcement, or to raise the level of the existing concrete with a cap of new reinforced concrete. I recommend the use of fiberglass reinforcement strands in any fresh concrete.

Q: I purchased a new townhouse here a year ago and am still having problems fixing small problems. My next door neighbor had a bad crack in her slab that cracked her sheet flooring. Then my other neighbor had a problem with a hardwood floor in her entrance hallway, they lifted up a piece of the wood and she had a crack in the slab more than an eighth of an inch wide. We are all conserned that there might be other cracks throughout the townhouses. Is the builder responsible to lift the carpets to inspect for more cracks as the house is still under warranty.

A: Your question is really a legal one, that we don't have the expertise to answer. I suggest that you take the text of the warranty to get legal counsel locally. It is not unusual for concrete to crack some after it cures, but this should be controlled by proper reinforcement so that such cracks are only cosmetic, not structural. The cracking that you describe is obviously excessive and likely the result of poor planning or workmanship.

Q: I have a cement foundation that is crumbling and I would like to replace it with real stone. I've had a lot of advice from everyone, but would like an expert opinion.

A: Replacing a foundation is a major undertaking and requires a good deal of skill and planning to do it right. Every situation is different, so only general precautions can be sent via the internet. I suggest that you find a local builder with experience in this sort of work to give some advice about your specific situation. The house needs to be adequately supported while the old cement is removed and the new foundation of stone is placed. This stone foundation will need to be seated below frost level. All of this can be done, but very carefully or you can jeopardize the integrity of the house, both immediately and over time.

Q: How can I figure out the depth of footings for house on piers or cinderblocks? Also, I am in south east Texas, so there is potential for flood or hurricane and I am not sure if that will make any difference to the depth.

A: Usually the depth of footings is determined by the frost depth in the area where you live, which I doubt is very deep in south Texas. I would suggest a "toe-in" of a good foot onto undisturbed soil for your piers. This should also give you ample flood and hurricane protection...but you might check this suggestion out with some of your local builders to see what they think.

Q: My wife & I live in Hawaii; our home is a Bali style with an Ironwood or Coconut (not sure which) shingled roof. My question is the wood is starting to show some cupping, bleaching & splitting and we would like to know is there ANY product we can use on it to extend the life of the wood? I forgot to mention that we are about 300ft from the ocean and the weather can be pretty extreme, and we catch our water from the roof to a 14,000gal catchement so the treatment needs to be safe for us to at least bath in. Also the water tends to have a slight rootbear color to it.

A: Unfortunately I am not really familiar with either ironwood or coconut being used as shingles for a roof, so I can't speak from experience. All shingles bear a great deal of hard exposure to the elements and cannot be expected to last beyond a reasonable time (about 35 years for cedar or redwood shingles). As for some product to apply that might extend their life, you might consider an oil (like linseed oil) that would soak in enough to replenish the natural oils. I suggest that you consult some local roof experts who have experience with what you have.

Q: I just want to know if you have any information on building a concrete slab, reinforced with straw?

A: (Kelly) I have heard of using straw as reinforcement in concrete instead of steel mesh. There have been some experiments with this in Canada, but this is not common. A few handfuls of fiberglass reinforcement would likely be much more durable and stronger.

Q: We have an old 70s stucco home. We would like to apply a thin plaster (smooth finish) of some sort to get rid of the old bumpy stucco look. Can you recommend an application for this? We are on a budget of course so Portland cementing over it seems like a waste of money. Thank you in advance for your advice.

A: (Kelly) I suggest that you check with a local stucco company to see what they recommend to smooth this out. It needs to be something that will adhere well to the existing stucco and be be very durable. I wouldn't rule out a cement-based product, since you would not be needing very much to do this job. I would imagine that just a smooth finish (color) coat is all that is needed.

Q: I was wondering how you preserved wood that is in the ground without using chemicals or too much concrete?

A: I don't think there really is a way to preserve wood in the ground, especially without chemicals. It is generally best to keep wood completely out of contact with the soil. There are some species that naturally last quite a long time with ground contact (such as cedar and redwood), but even these will decompose over time. I have heard of people charring the ends of buried logs to delay rot, but I don't know how well this really works.