Tuesday, November 10, 2015

Decks for DIY Dummies (Carpentry Week 3)

Free-standing deck schematic
Without a doubt, the most popular DIY project for homeowners is building a deck. It's probably the project responsible for the sale of more of Home Depot's crappy treated lumber than any other. The problem being, of course, that an average first-time deck-builder barely knows which end of a hammer to use for driving screws, so it's off to google to look for help. With luck, that DIYer will end up at a site written by a pro – or at least someone who's done the job. If, however, the stars are misaligned, the poor DIYer might well end up getting instructions from someone who – maybe – once watched a deck project. Someone like, say, Liz Elias (DzyMsLizzy) from Hubpages.com niche site "dengarden.com," seen here writing (sort of) about "How to Build a Free-Standing Deck." At least she hyphenates correctly...

Like most "hubs," this one is long and chock full of factoids and instructions. Unlike a lot of the rubbish you find at eHow, most of it's... well, we don't want to say "correct," so we'll just say "inoffensively semifactual." Liz, however, does get some stuff wrong – or at least misleading. Take, for instance, the whole section about grading:
"Next, you must lay out your plot markers, then grade the site. This is done by means of stringing lines tightly between sturdy stakes marking the perimeter. You can either hire someone with experience operating a grader, or level your plot by hand..."
Why? Unless there's some truly weird topography, you're just going to make the deck flat by adjusting the height of the support posts. If there's significant slope, no way can you simply lay a deck on skids. Grading is for slabs and patios, not decks. Then there's
"...place your pier blocks, and insert your 4-inch x 4-inch posts into the tops. This provides the support for your framing. The larger the area, the more blocks and posts you will need. Generally speaking, you should have a support for every four feet of deck...."
Gonna just set those pier blocks on the ground? Not a good idea in a place that has frost. That's not to mention that she just told you to "grade" the area under the deck, which means the piers would be set directly on disturbed soil – a no-no. By the way, Ms Elias, what does "every four feet of deck" mean? And then there's
"...be sure to allow for the 6-inch dimension of the joist lumber with the blocks inside the perimeter...."
Only the smallest decks are built with 2 x 6 joists -- at least suggest that the builder consult a table of joist sizes, Liz! More bad instructions ensue:
"Attach the framing to the support posts with bolts run all the way through both the framing lumber, brackets made for the purpose, (called joist hangers), and the support posts."
We don't follow, Dizzy: are you saying that these bolts run through joist hangers? That's not how joist hangers work! And, for what it's worth, a careful (or professional) deck builder uses saddle connectors to lay the deck framing on top of the support posts instead of bolting framing members to the posts. When it comes to hanging her joists, Liz tells us that
"Use joist hangers on the insides of the main support posts of the frame, with the bottom of the bracket at 5 and ¾ inches below the top of the post top"
You've got two major problems there, Liz:
  1. You don't attach joists to vertical support posts – you attach them to the horizontal supporting beams
  2. If you do use 2 x 6 lumber, it isn't 5¾" wide: it's 5¼" wide, so placing the hangers according to your instructions leaves a half-inch gap – though we honestly can't tell where it leaves it, since you don't have any other framing...
You get the picture, right? Dizzy Ms Lizzy just tried rewording the instructions she found elsewhere (perhaps these) that were written by a professional, but in the process got confused by her complete lack of knowledge about how one actually builds decks. You know what doing that makes Liz, don't you? It makes her a dumbass – our Dumbass of the Day!
copyright © 2015-2023 scmrak

DDIY

No comments: