You need to do a little more archeological digging still. You need to know the whole construction of the floor before you can decide how best to install something new. I'd take up that plywood piece in the kitchen and see what's under it. It's higher than the surrounding floor, so needs to go. You should also be able to see from there what subfloor is under the original kitchen hardwood. It's too bad the space under your entryway is finished, but I'd still do some exploring from below to see what's under there, and to figure out the fix to stop it from squeaking. Is it drywall below or a drop ceiling? I know it probably seems like a pain to tear out drywall, but if you cut out a clean patch, like 2' x the width of the joists, it'll be relatively simple to repair. Just make sure to cut it down the center of the joists so that there's room to screw the patch piece to it later. Cut the hole under the area that squeaks the most, if you can. Have someone walk on and watch the floor from below to see what's moving. It might be as simple as pounding in a couple shims from below, or face-nailing a loose board from above. You want to find out what's underneath the hardwood. It might be laid directly on the floor joists, or there might be 10" wide boards that the hardwood is nailed to. Another thought is to take out a board in the hallway, since that's not original and you want to replace it. See what the subfloor is there. I am a bit puzzled at why, when you've stripped the kitchen down to the original hardwood, it's still higher than the hallway floor. Is your current surface perhaps not the original kitchen hardwood? Peeling back the plywood area will help determine that. BTW, I haven't heard of that stop squeaking product you linked to, so can't offer any personal opinion. And don't pour self-leveling compound over top of hardwood. It needs to go over plywood.

I'm having the same concern. I originally went to lumber liquidators and found a nice hand scraped strand bamboo flooring. I then went online and researched a load of companies. So far, I like Cali bamboo. My biggest concern was the formaldehyde in the products. Cali bamboo has little to no formaldehyde added in there product. I've read those same reviews about Morning star, but they were outdated. I was emailed a material safety data sheet on Morning Star brand, but no one could tell me how much formaldehyde content was in the morning star product. At the bottom of the sheet there was a disclaimer: "The information and data herein are believed to be accurate and have been compiled from sources deemed to be reliable. It is offered for your consideration, investigation and verification. Lumber Liquidators makes no warranty of any kind, express or implied, concerning the accuracy of completeness of the information and data herein. Lumber Liquidators will not be liable for claims relating to any party's use of or reliance on information and data contained herein regardless of whether it is claimed that the information and data are inaccurate, incomplete or otherwise misleading. It is incumbent upon the user to obtain the most up-to-date information". So I guess what they mean is that the info on the safety data sheet is BS. I'd like to know. Cali bamboo is great, but I actually prefer the hand scraped look they have from Morning Star at lumber liquidators. Does anyone know if Morning Stars 2011 line has added formaldehyde?? (That's the lovely odor you smell from the floors). I can't seem to be able to get a solid answer. This is what the safety data sheet states for Morning Star: 3000 John Deere Road Toano, VA 23168 Emergency phone: 1 800-HARDWOOD Fax: 1 757 259 7295 IMPORTANT NOTICE: This material Safety Data Sheet (MSDS) is issued by LUMBER LIQUIDATORS. LUMBER LIQUIDATORS flooring will issue a new MSDS when there is a change in product specifications and/or regulations. LUMBER LIQUIDATORS will not accept any responsibility for any change to its MSDS in content by other person or organization. IDENTIFICATION Product name: Prefinished Strand Bamboo Flooring Trade name: Morning Star Bamboo Flooring Other Names: Various Manufacturer Information: Lumber Liquidators Inc 3000 John Deere Road Toano, VA 23168 Tel: (757) 259-4280 Fax: (757) 259-7295 www.lumberliquidators.com Description: This product is composed of bamboo fibers bonded together with urea formaldehyde (UF) resins. The fibers are mixed and pressed together to give a unique shade blend and increase hardness. The wear layer is finished by 7 coats of polyurethane with aluminum oxide coating manufactured by Treffert or Klumpp UN number: Not applicable Dangerous goods class: Not applicable Product Use: Building Materials � Commercial or Residential MSDS Morning Star Strand Bamboo Flooring, Revision 3, April 2009 Page 2 of 7 Hazardous ingredients/identity information: Name CAS #2 % Agency Exposure Limits Comments Bamboo1 None 89-90 OSHA3 OSHA ACGIH4 ACGIH PEL5-TWA6 15 mg/m3 PEL-TWA 5 mg/m3 TLV7-TWA 3 mg/m3 TLV-STEL8 10 mg/m3 Total dust Respirable dust fraction Respirable dust fraction Inhalable particles Urea Formaldehyde resin solids 9011- 05-6 10-11 OSHA OSHA ACGIH PEL-TWA 0.75ppm PEL-STEL 2 ppm TLV - Ceiling 0.3 ppm Free gaseous formaldehyde (contains less than 0.1% free formaldehyde) UV Finish Polymerized polyurethane None 0-1 OSHA ACGIH PEL-TWA none TLV-TWA none None None 1 CAS # = Chemical Abstract System. 2 OSHA = Occupational Safety and Health Administration. 3 AGCIH = American Conference of Government Industrial Hygienists. 4 PEL = Permissible Exposure Limit. 5 TWA = Time Weighted Average. 6 TLV = Threshold Limit Value. 7 STEL = Short Term Exposure Limit Note: Bamboo is a member of the grass family which has distinct anatomical differences from that of wood. Therefore, bamboo would be regulated as an organic dust in a category known as "Particulates Not Otherwise Regulated" (PNOR), or Nuisance Dust by OSHA. The ACGIH classifies dust or particulate in this category as "Particulates Not otherwise Specified". Physical data: Physical State: Solid Boiling Point: Not applicable Freezing Point: Not applicable Specific Gravity: 0.58 g/ml Vapour Density: Not applicable % Volatiles By Volume: 0 Melting Point: Not applicable Vapour Pressure: Not applicable Percent Moisture 5% - 9% Solubility in H20 (% by wt.): Evaporation Rate (Butyl Acetate = 1): Not applicable pH: Not applicable MSDS Morning Star Strand Bamboo Flooring, Revision 3, April 2009 Page 3 of 7 Appearance and odor: Bamboo fibers mixed creating a shade blend unique to each plank (light yellows for natural, light browns for carbonized or a mix of lights yellows and light browns shades). This product can also be stained with various colors. Low-fuming urea formaldehyde resins have a slightly aromatic odor. Fire and explosion data: Flash Point: Not applicable Auto ignition Temperature: Not available, however, it is usually accepted that the ignition of bamboo begins when the temperature reaches 204-260�C (400�500�F). (Depends upon duration of exposure to heat source and other variables). Explosive Limits in Air: Not applicable. See below under "Unusual fire and explosion hazards" Extinguishing Media Water, Carbon dioxide, Dry chemical, Sand. Special Fire Fighting Procedures None Unusual Fire and Explosion Hazards Sawing, sanding or machining can produce bamboo dust as a by-product which may present an explosion hazard if a dust cloud contacts an ignition source. An airborne concentration of air is often used as the LEL for bamboo dust. Reactivity data: Conditions Contributing to Instability Stable under normal conditions Conditions to avoid Excessive moisture, condensation or water vapor; Open flame or conditions above 400 F. Incompatibility Avoid contact with oxidizing agents. Avoid open flame. Product may ignite when temperature reaches in excess of 204�C (400�F). Hazardous Decomposition Products Thermal and/or thermal oxidative decomposition can produce irritating and toxic fumes and gases, including carbon monoxide, hydrogen cyanide, aldehydes, organic acids and polynuclear aromatic compounds. Hazardous Polymerization Not applicable MSDS Morning Star Strand Bamboo Flooring, Revision 3, April 2009 Page 4 of 7 HEALTH HAZARD INFORMATION Carcinogenicity Listing: (X) NTP1: Group 2, A & B Formaldehyde, Wood dust NTP-Group 2: Reasonably anticipated to be a carcinogen. A) Limited evidence of carcinogenicity from studies in humans which indicates that causal relationship is credible. B) Sufficient evidence of carcinogenicity from studies in experimental animals (X) IARC2 Monographs; Formaldehyde, Group 2A, Wood dust, Group 1 IARC-Group 1: Carcinogenic to humans; sufficient evidence of carcinogenicity. This classification is primarily based on studies showing an association between occupational exposure to wood dust and adenocarcinoma of the nasal cavities and paranasal sinuses. (X) OSHA3 Regulated: Formaldehyde IARC-Group 2A: Probably carcinogenic to humans; limited human evidence and sufficient evidence in experimental animals. Studies of cancer incidence among workers in a wide variety of occupations have failed to convincingly show carcinogenic activity of formaldehyde in humans. Gaseous formaldehyde has been shown to cause cancer in certain laboratory animals after long-term exposure to very high concentrations (14+ ppm); concentrations which are far above the levels of formaldehyde gas emitted by this product. 1 NTP = National Toxicology Program 2 IARC = International Agency for Research on Cancer 3 OSHA = Occupational Safety and Health Administration Exposure hazard: Eye Contact Wood dust can cause mechanical irritation such redness and watering. Skin Contact Not applicable for this product in its purchased form, however various species of wood dust may evoke allergic contact dermatitis in sensitized individuals. High concentrations of gaseous formaldehyde may cause allergic contact dermatitis. Ingestion Not likely to occur under normal use. If ingested, may cause gastrointestinal tract irritation. MSDS Morning Star Strand Bamboo Flooring, Revision 3, April 2009 Page 5 of 7 Inhalation Not applicable for this product in its purchased form, however, wood dust may cause nasal dryness, irritation and obstruction. Coughing and sneezing; sinusitis and prolonged colds have also been reported. Wood dust, depending on species, may cause respiratory sensitization and/or irritation. However, gaseous formaldehyde may cause respiratory difficulties for sensitized/allergic individuals. Emergency and first aid procedures: Eyes Flush eyes with large amounts of water. Remove to fresh air. If irritation persists, get medical attention. Skin Wash affected areas with soap and water. Get medical advice if rash or persistent irritation or dermatitis occurs. Inhalation Although not applicable for this product in its purchased form. However, if inhalation of bamboo dust, remove to fresh air. Get medical advice if persistent irritation, severe coughing or breathing difficulty occurs. Ingestion Not applicable under normal use. PRECAUTIONS FOR USE Accidental Release Measures Not applicable for product in purchased form. Dust generated from sawing, sanding, drilling, or routing of products may be vacuumed or shoveled for recovery or disposal. Avoid dusty conditions and provide good ventilation. A NIOSH-approved dust respirator should be worn if dust exposure limits are exceeded. Handling and Storage No special handling precautions are required for products in purchased form. Keep in cool, dry place away from open flame. This product will release small quantities of gaseous formaldehyde (≤0.12 mg/m3, which is below the E1 classification in accordance with EN 717-1:1998 test methods). Store in well ventilated area. MSDS Morning Star Strand Bamboo Flooring, Revision 3, April 2009 Page 6 of 7 Personal Protective Equipment: Respiratory Protection Not applicable for product in purchased form. A NIOSH-approved dust respirator is recommended when allowable exposure limits are exceeded. Protective Gloves Not required. However, cloth, canvas, or leather gloves are recommended to minimize potential mechanical irritation slivers from handling and machining product. Eye Protection Not applicable for product in purchased form. Goggles or safety glasses are recommended when machining this product. Other Protective Clothing or Equipments Not applicable for product in purchased form. Outer garments may be desirable in extremely dusty areas. Work/Hygiene Practices Follow good hygienic and housekeeping practices. Clean up areas where wood dust settles to avoid excessive accumulation of this combustible material. Minimize blowdown or other practices that generate high airborne-dust concentrations. Local Exhaust Provide local exhaust as needed so that exposure limits are met. Special / other None OTHER INFORMATION Disposal Consideration If disposed of or discarded in its purchased form, incineration is preferable. Dry land disposal is accepted in most states. It is, however, the user�s responsibility to determine at the time of disposal whether your product meets RCRA criteria for hazardous waste. Follow applicable federal, state, and local regulations. Transport and Regulatory information Not regulated as hazardous material by the U.S Department of Transportation and the Canadian Transportation of Dangerous Goods (TDG). Not a controlled product by WHMIS

We carried the wood into our tiny powder room since the whole downstairs was wood. In our house it seemed to make the most sense. However I don't have a problem with transitioning floors (that's what thresholds are for ;-) ) as long as it's maybe just once. I'm not crazy about a different floor in every room. I think if the whole downstairs is wood then having marble in the powder room would be fine, if that's what you want.

Wood vs. Engineered Wood? No contest in this case. If the home was built in 1905, put real hardwood in. This preserves the integrity of the home's building materials. Plus, as you can see from the age of these floors, higher grades (i.e. thicker) hardwood can be sanded several times; you usually don't get even one chance to sand engineered wood. The hardwood layer at the top of this multilayered product is simply too thin. Level Floors and Subfloors There are ways to level a subfloor, ranging from replacing parts of the subfloor with thicker or thinner sheets of plywood (or planks, see below), to pour-on leveling compounds that harden to make the entire floor level. What you use to level uneven areas depends on what the subflooring is. If it is plywood or concrete, the compound works. But more likely with this home, on floors at or above grade, there will be wood planks laid at a diagonal across the floor joists. So in your home, the layers were probably joists first, then subfloor planks of wood, then hardwood with tongue & groove joints. You cannot effectively use a pour-on leveling compound on a plank subfloor, as there are cracks between the planks. However, you can lay a new hardwood floor directly on a wood plank subfloor as long as those planks are sound and relatively level. Replace individual planks that have been damaged by water or insects, are otherwise compromised, or even missing (it happens!), with either new planks of lumber, or with plywood of the same thickness as the planks. Any lumber you install, for either the subfloor or finished flooring, should be brought in to your home several days prior to installation, so the materials acclimatize to your typical interior temperature and humidity. Unlike for ceramic or porcelain tile, the subfloor does not have to be perfectly level. And unlike vinyl sheeting, planks or tiles, the hardwood won't "telegraph" minor differences in height, and minor surface irregularities, so the subfloor doesn't have to be absolutely perfect; it should be sound, strong, uniform and essentially level. Your flooring contractor can give you specifics on what upgrades your subfloor may need once the original hardwood is removed. Joists If the floor is significantly not level in parts, or if certain areas feel spongy when you walk on them, I recommend you have your flooring contractor, a home inspector, or structural engineer inspect the subflooring and especially the floor joists. You don't want to invest in a new floor, only to have it become damaged because some joists weren't attended to. Transitions Transitions (a.k.a. thresholds or molding) between existing rooms and the new floor ought to be made of the same wood and same finish (stain, polyurethane, etc.) as the new flooring you are putting down. As wood ages, the finish becomes darker, so trying to make the transitions match the finishes of existing floors is very difficult and not recommended (what will match those floors right now won't match later after your transitions age up a bit). Eventually, the transitions wouldn't match either the new or the old floors! Transitions come in four types: reducer (when the two floors being joined are of different heights), seam binder (when the floors are the same height, and the boards from each are very close to one another), T-mold (when the two floors are the same height, but there is a crack between the two rooms' flooring) and stair nose or stair edger (when the flooring needs to curve around the front of a stair's "tread"--the flat part of a stair upon which you tread!). The transitions for your particular project can be ordered when you order the hardwood, so make sure to include measurements for those doorways/entrances. The contractor can tell you if he/she anticipates there will be a height difference or gap between the floorings, which would require those particular transitions. Dry Air Concerns Consult a local lumber supplier or flooring contractor familiar with your local climate conditions to discuss finishes or other tips for keeping your wood floors healthy in the dry winters. Sounds wonderful! Have fun!