awood91
Active Member
- Joined
- Jun 7, 2006
- Messages
- 458
- Reaction score
- 476
Because it isnt PapIEr MaChÉ?
101-105 Washington St. | Mixed Use Complex | Brighton
- Thread starter bigpicture7
- Start date
CIP concrete construction (compared to the paper and glue most new resi projects are made of), continuous brick shelves and tie-backs mean we're going to see actual laid brick (piles of brick seen in some of these photos), not some cheapo veneer stapled onto fiberboard, the lack of obtrusive vents or PTAC units means that the building has an actual HVAC system. That doesn't mean I actually like the building or think it will look nice, but it is a superior quality to the majority of new homes being built in the city today.
(People make fun of me for being a pest about construction quality, but this stuff should be a constant topic for discussion on an architecture forum.)
awood91
Active Member
- Joined
- Jun 7, 2006
- Messages
- 458
- Reaction score
- 476
Can you please cite some sources that explain what is wrong with wood framed construction? I am genuinely interested to learn why you say this is the case. If it is so bad wouldn't it be outlawed in building code? And are all single family houses just boxes of shit because they are made of wood?
Plen-T-Pak
Active Member
- Joined
- Jul 23, 2007
- Messages
- 232
- Reaction score
- 455
Aw man, we were so close.
These buildings aren’t made of wood in the sense that a three decker in Dorchester is made of wood. These are made of very low quality chips of random wood that are pressed into sheets with urea-formaldehyde as a binder, then saturated with fire- and insect-resistant chemicals. This is wood construction in the same sense that the “pink slime” McNuggets are made of actual chicken.
From a performance perspective, these are very lightweight buildings with the worst acoustic and vibration characteristics this side of a tepee. You hear and feel everything on all sides. Insulation values are terrible. They do, however, behave very well in high seismic conditions.
Type V-B buildings are obvious fire hazards and have indeed been outlawed for multi-family construction in dense municipalities, particularly all of Manhattan, Brooklyn, the Bronx, and much of Queens. You’re surrounded by combustible materials on all sides and depending on the proper functioning of a sprinkler system to save your bacon. The guy frying a whole butterball in the unit above you is separated by two layers of 5/8 chipboard - do you trust that your landlord has kept the sprinklers to NFPA 25 standards?
Cheap looking tacky finish materials, unskilled non-union labor, dimensionally unstable material for an integral structural purpose, etc etc. The entire thing screams “27.5 year IRS depreciation schedule” and that’s it.
awood91
Active Member
- Joined
- Jun 7, 2006
- Messages
- 458
- Reaction score
- 476
Ok thanks, was an interesting read. Is type IV (cross laminated timber) considered significantly preferable as far as integrity goes? Is a dorchester triple decker just type V?
Sorry I ‘made fun’ of your papier maché comment but you’ve been saying it over and over again with this unpleasant disdain that was annoying haha - but appreciate the overview.
From the sounds of it, you could poke one of these buildings with a pillow and knock it over.
They are, structurally speaking, just fine. They’re not going to blow over or collapse on themselves. They are just the bottom of the barrel in terms of materials and I would not want to take out a thirty year mortgage for a building with Route 1 motel chintziness. And I certainly wouldn’t want to build entire cities out of them!
A triple decker doesn’t qualify as type IV construction, which requires larger timber sizes than those buildings contain. I haven’t been in a ton of triple deckers, but they do also tend to be huge fire risks. Don’t we get a story about one of these burning down on Christmas Eve every year?
Triple deckers were built outside the fire district, three units per building, and they almost always have a setback distance from the lot line to provide separation from the similarly combustible neighboring buildings. They’re obviously not sprinklered like 5 over 1s are, but at least one conflagration isn’t going to endanger hundreds of units.
Type IV is not necessarily Cross Laminated Timber (CLT). It is part of the Type IV construction type, but as king_vibe alluded to, Type IV is specific for heavy timber in general which is much larger members that are still combustible, but have much different burn characteristics then light frame.
That being said, light frame construction certainly still has its place within the construction industry. The reason light frame is still used in low density or single family housing is because it is the most cost effective material to build with at that scale. The International Residential Code also has a lot less requirements because the occupant load of that building is much less. The IRC can be used in multi-unit construction up to a certain number of units only though, so there is a cap on that.
In the commercial world, Type V can be very useful in building low to mid density construction. Type V construction may have the least amount of restrictions, but they also allow for the least amount of building space. Type III construction allows for light-frame that is fire treated and has been proven to be quite safe. Is it combustible still? Yes. But when you are building Type III or Type V buildings all those assemblies (walls, floors, roofs) are all required to be tested and survive a certain amount of time in fire conditions. The 5/8" "chipboard", ie gypsum board (specifically Type X gypsum board), is a non-combustible material (unlike wood) that is proven to survive fires much better than combustible materials (wood). Orient Strand Board (OSB), referred to as "very low quality chips of random wood that are pressed into sheets with urea-formaldehyde as a binder" is also tested for fire resistance, lateral forces, seismic forces and all the other tests that proves the material is safe. Each apartment/condo/dwelling unit within these large buildings are required to be separated from one another via these fire tested assemblies. The ratings are designed to allow occupants to exit the building safely prior to catastrophic events. Some parts of the building codes allow these ratings to be stepped back slightly when a sprinkler is present, but those ratings are never allowed to go away. If some folks are concerned about fire sprinkler maintenance, maybe they should go around town and judgingly call the fire department over concerns of maintenance.
As for thermal and acoustic qualities in the buildings, I would say construction error is a bigger player in that realm then the material itself. Thermally, wood studs actually perform BETTER than metal studs because they less conductive then metal. While wood studs still allow a certain amount of thermal bridging, it is less than what metal allows. The building codes have also worked to eliminate this by introducing the continuous insulation (ci) requirements. While there are ways around the ci requirements in the code, the intent is there. Acoustically, there are many solutions to sound such as the code requirements for Sound Transmission Class (STC) between units, just like the fire ratings. While the ratings are pretty low by my standards, many architects design to improve those ratings. For example, the floor of a wood constructed unit will many times be designed to have the wood subfloor + acoustic mat (thickness varies, I try for 3/8" whenever possible) + gypcrete + finish floor. The acoustic mat and gypcrete are typically large Value Engineering elements to save cost on the project.
I find the almost fear-mongering level of criticism of light frame construction to be a bit much.
All this to say, light frame within urban cores does raise some eyebrows for me. When we talk about sustainable development and longevity in buildings, light frame to me doesn't jump off the page. The skilled labor that builds light frame is typically lower than those of steel, concrete and mass timber. I personally don't care if it union labor or non-union labor, I have seen both have its issues. There are more points of possible failure on the human end of light-frame construction then there are on the material end and ultimately there always will be. I am a HUGE timber proponent, Mass Timber specifically, but even light frame is a very sustainable building material if harvested and manufactured correctly. While I don't necessarily believe an outright "ban" is the correct path for light frame in urban cores, a policy change to allow more density to get developments to larger densities in which light frame is less enticing may be an option.
Plen-T-Pak
Active Member
- Joined
- Jul 23, 2007
- Messages
- 232
- Reaction score
- 455
Excellent post. Thanks so much for this.
Good on you, awood91. You actually pushed him to try to make a substantive post, instead of one of his usual edgy hawt taykz!
stick n move
Superstar
- Joined
- Oct 14, 2009
- Messages
- 11,195
- Reaction score
- 15,394
Nice addition.
I'll bet they got a deal on Gas Stoves. Not a foodie so dunno if there's any Foodie reason you would want Gas over Electric, when yes, Boston is likely to ban it soon enough.