Thursday, April 26, 2007

slate roof update - tower 50% complete

Just a quick picture update of our slate roof progress. We've worked about 15 man-days on the tower slate so far... It is not really as complete as the picture might lead you to believe.We have a lot more slate to put on the back side of the tower, but I like how it looks so far, so I guess we'll keep going! The fish scale slates are for my wife - she thinks I'm a slacker for not doing the whole house with that style of slate.

I hope to find some kind of weather-vane, compass, finial, lightning rod, or combination thereof, to place on top of the tower. Has myth-busters done an episode on lightning rods yet? Does anyone know if they actually work?

Tuesday, April 17, 2007

Back on the roof

Just as I was beginning to enjoy working indoors and building our stone fireplace, mother nature served a rude wake up call that our roof was not finished. During a rainstorm this past weekend, I went up to the top floor of our house and discovered not one, but two rapidly growing puddles of water inside the house. The water was coming in exactly where we quit roofing last fall when the weather turned nasty. Monday morning I called my bro-in-laws to warn them... "dress warm, we're going back up on the roof."
I have been dreading roofing the tower. The steep pitch of the roof is not really a concern, because we can work from the relative safety of a crane platform. (I'll take a 33 yr. old crane over a brand new ladder or rope any day.) What I dreaded was slating the hips - there are 8 hips on the tower roof. In case you missed the other roofing posts on this blog, we made a decision to use mitered style slate hips on the house. This means that each ajoining pair of hip slates must be precisely cut and fitted together, and that proper flashing must be cut, broken, and interwoven between the courses of hip slates.
As with the main roof, I chose to use terne-coated stainless steel. It is a little cheaper than copper and will probably last much longer. I must have done something right on the hips of the main house, because they weathered the entire winter without admitting a single drop of water and none of the hip slates shifted or moved - as far as I can tell. Rather than bend the flashing point-to-point as I did on the main house, for the tower I decided to bend the flashing right down the middle. The geometry of the corners of the tower is a lot different than the geometry of the hips of the main house. Also, because the slope of the tower transitions from 21:12 to 12:12, every one of the hip slates has to be scribed and cut to fit. Even with the added complications, slating the tower hips is going much easier than slating the hips of the main house. The dread was worse than just getting up on the roof and starting this job.
Getting the side lap on the hip slates and field slates to work out right is not something that just "happens." (at least not for me!!) Symmetry is especially hard to achieve when laying slate "by the seat of the pants." To avoid time consuming mistakes (the ones where you lay 3 or 4 slates and then decide you need to rip them off the roof!), and to make sure the style would suit my wife as well as me (i.e. to avoid ripping all of the slate off after the thing is done!), I laid out the pattern for the tower roof on my computer before laying the first real slate. It is not as important for the rectangular slate that you see here, but further up the roof, where the pitch of the roof is no longer changing, I plan to use "fish scale" shaped slates. I really don't want those to look random. Whereas the roof of the main house has an informal roof style created by "staggered butt" and "random width" slates, I want the tower roof to look somewhat more formal. I'm not worried that the styles will clash, because the color and texture of the slates are identical and should tie the two roofs together. In fact, I doubt most people will notice at first glance. That's what I'm after anyway!

Starting the stonework

I've finally started laying some stonework for our fireplace. It's slow but fun! My original thought was to have a professional mason lay up our fireplace and chimney with blockwork, and then as time permitted I would go back and face the blockwork with stone from our farm. But as I'm learning with this house, it really pays to think about your plans and to see if there isn't a simpler, cheaper solution before you dive in. (or maybe all this "thinking" gets me in trouble - which is it?)

Although a blockwork fireplace would provide a solid and plumb guide for stonework, it would impose the additional constraint of using stones of a somewhat consistent thickness. (think "bricks" or the fake glue-on stones that you see in restaraunts.) I recently came upon the seemingly credible idea of pouring a fireplace from, and that has intrigued me. I've also been fascinated with slipform masonry, but the results of slipform masonry seem... sloppy. What I've decided to try is to lay up my stone first, mortar it slightly so that it looks like drylaid stone, then pour against the backside of the stone slowly, in short lifts - bracing the stonework of course against the pressure of the concrete. Maybe it will work. I'm going to find out.

These pictures show are the results of my dry-stacked prototype so far (no mortar). The large picture at the beginning of this post shows the view of the fireplace structure from the 3rd floor loft. The fireplace faces east. Backing up to the fireplace, facing west, is an alcove for the wood cookstove. I will use block (as shown here) with poured cores or concrete forms for the cookstove alcove. Facing south will be the wood fired bread oven (not shown) and directly beneath the bread oven will be back to back wood storage alcoves for the kitchen and greatroom.

The idea, to state it another way, is to build the perimeter of my fireplace structure with stone, brick, or even CMU - whatever is most appropriate, brace it all, and then pour the inside of the structure full of concrete.

The last picture shows the backside (inside?) of my stonework. As you can see, stones of varying thickness can be readily acommodated, and the uneveness of the wall should help to bond the stones to the structural concrete that gets poured behind them. I have a book on stonework (sorry I will provide a reference later) that is a proponent of a similar approach to stonework.

Monday, April 16, 2007

Building a Rumford Fireplace - Part I

Rumford fireplaces are differentiated from typical American fireplaces by their tall/shallow fireboxes, their streamlined throats, and most importantly... by their promise of actually producing more heat than they waste! They are designed to maximize the direct and reflected radiant heat from the fire in your fireplace. For everything you ever wanted to know about Rumford fireplaces, see For one person's experience, building a Rumford style fireplace in a timber frame home, keep reading,and stay tuned!

Having a genuine desire to build my own functional fireplace, but possesing no real knowledge of proper fireplace proportion and design, I decided to buy a 48" kit from Superior Clay Corporation. In exchange for my money, they shipped to me: a lot of firebrick, a refractory throat, a two piece clay smoke chamber, a cast iron damper, clay flue liners, refractory mortar, and instructions for building my own fireplace. (One could also buy prebuilt firebrick walls from this company, but I decided to lay-up my own, based on their straightforward instructions.) Everything arrived promptly and in perfect condition. Most of the "magic" for getting the proportions (and draft) correct seems to be in the design of the throat (pictured at right).

Step 1. Laying the firebrick hearth. After reading the directions, drawing dimensions on my slab, dry-laying some bricks without mortar, and checking the dimensions of my unmortared hearth with the dimensions of throat, I was ready to mix mortar and put the hearth together. This step was fairly easy. I mixed the mortar fairly wet (looked like cake icing), buttered the bricks, and squeezed them into place one at a time such that the joints were 1/16th to 1/8th of an inch apart. This particular refractory mortar "sticks" the bricks together within a few seconds, but takes a long time to dry. At a few points I was unsatisfied with my work, so I pulled the offending bricks back up, scraped off the mortar, applied new mortar and placed those particular bricks again. No pressure to hurry. In fact, the mortar was easy to wipe off - even an hour later, so it was OK to be sloppy as well.

Step 2. Laying the firebrick for the sides of the firebox. The back of the Rumford style firebox has a flat side and two angled sides. At first I thought I should weave the brick courses of the three sides together for strength. But then I realized that the kit (no matter which size you buy) is thoughtfully designed to use exact full-brick and half-brick increments. I also realized that in order to weave the bricks together, some would have to be cut on a 45 degree angle, which would leave a thin sliver of brick that might be more prone to breaking or spalling. The full-brick-halfbrick design suggested in the instructions is about the best you can do, aesthetically, without going to something like a herringbone pattern. Ultimately, it seems that these firebricks are more of a "liner" than a structural element of the Rumford fireplace kit, so I have no qualms about laying up the three sides of the firebox seperately. The trick to laying these bricks seemed to be... keeping the courses level, keeping the courses straight, and keeping the joints a consistent thickness.

Step 3. Laying up the structural backing. Here's where I've decided to deviate from the instructions - slightly. Although not specifically mentioned in the printed instructions, the web site for the rumford kits suggests that you might want to pour your fireplace structure, rather than lay it with block. This is the route I have chosen. Of course, concrete at anything over a few inches thick, has some incredible force pushing outward while it is in liquid form. I have decided to pour no higher than 2 feet at a time, and I will "kick-off" or otherwise support this brickwork when I pour against it. The web site also advises to make provisions for a bond-break (or even better - an expansion gap) bewtween the firebrick and the poured cement backing, if you chose to pour cement. More on that when I get to it. For the conventional block fireplace route, see the instructions on their web site.

Here you are looking at the only brick I have ever laid in my life. I'm proud of it so far! 5 courses of brick (laid on edge - these are called "shiners") equates to about 2 feet of height. The fire box will eventually be 10 courses high - or nearly 4 feet tall, before the throat is mortared on top. In the bottom of the hearth, you can see I have left one brick out (and a hole beneath the hearth) to serve double duty as a "fresh-air make up" / "ash dump." Perhaps I will make or order a trap door set-up for this hole. In the mean time, a loose brick will serve the prupose.

In the left of the last picture (and in the right of the second-to-last picture), you can see a partial 36" bread oven kit - from the same manufacturer. The bread oven kit (aka wood fired pizza oven) is just sitting there now so that I know it will fit when I bring the entire masonry structure up to about 4 feet and start incorporating it with the fireplace. I'm more excited about the bread oven than I am the fireplace (my wife's a great cook!), so I'll be sure to document its construction as well.

Concrete is always exciting

Four years ago, we did a little project on this farm that required some concrete. To make a long story short, on that project, a concrete truck went "wheels up" with 10 yards of concrete in the drum and yes, the concrete set-up in the drum before we could get the truck upright. We've poured cubic 300 yards since then, but still, every time we pour concrete, my adrenalin gets pumping. I've noticed the same thing happens with seasoned concrete people too. Concrete has a way of making people nervous.

Last fall, the dirt road to the house site became too muddy before we could pour the slab for our fireplace. Given my previous luck with concrete trucks, I decided not to press my luck. We boxed in the house, added (most of) a roof, and waited for better weather. A few days ago, I declared the road "almost passable" and decided it was time to finally pour that slab in the middle of our great room. The forms had been ready for weeks - there were just a few knick-knacks to take care of... some rebar to secure... and a road to smooth out... so I ordered 4 yards of concrete for 12:30 pm. One of my bro-in-laws hopped on the backhoe and started hauling "crick rock" to some of the rough spots in our road. I followed behind him on the dozer and graded the road smooth. My other bro-in-law removed some rigid insulation from our house so the truck could shoot concrete through the hole in the wall when it arrived.

By 11:30, the road looked fine, so one of my b-i-l's jumped in his truck and headed home to get the concrete tools and some food. At 11:57 I looked at the clock in my truck and thought about going to grab some food too before the concrete truck arrived. But then I looked down the hill to the main road (half a mile away and 300 feet down from the house site). Was that our concrete truck coming up the road? half an hour early? Impossible - they're never early. Just then the truck turned off the main road and came across an abandoned road through one of our fields, headed straight for the creek. The driver had been to our site almost 18 months ago... before we had a bridge, and had just assumed that we were still driving through the creek. Not so! In fact, I wasn't even sure one of my tractors could go through that creek location after the spring gully washer we had received recently. Panicked, I jumped in my truck and raced down our hill to try and re-route the driver before he attempted to cross the creek. By the time I got to the creek, the driver had already drove through it and was grinning. "You crazy son-of-a-gun!" I yelled - "we have a bridge - you didn't have to go through the creek." "Awwwwl, that's the funnest part!" he said.

My b-i-l showed up with the concrete tools just as we were ready to pour the first concrete into the forms. At that point I realized that I had absent-mindedly left the concrete vibrator on the other end of the farm. So, off the hill I drove once more - knowingly violating what I think is one of the most important rules of concrete - "never leave the pour!" "Don't let your brother add too much water... please," was my last request before I ran for the concrete vibrator.

By the time I got back, half of the forms were full, the slump looked fine, the forms weren't leaking into the basement, and everything was under control. In fact, by 12:30 (when the truck was scheduled to arrive), we were done with the fireplace slab and had finished pouring the leftover concrete into the cores of some cinderblocks (these cinderblocks form the below-grade stone ledge around my basement.)

Minutia and technical stuff for the DIY folks:

In picture #2:

*the blue conduit is for electrical service to the mantle. A few weeks ago my cousin reminded me not to forget the wires to the mantle before I started building my fireplace. She said she has to run an extension cord up the front of ther fireplace to her christmas lights.

*the white painted doo-hickies are ends of oak timbers. Rather than frame my sill timbers around the fireplace structure, I got lazy and poured the dovetailed timbers into the fireplace slab. I pity the folks that try to replace these timbers in a few hundred years. The white paint is to keep the water in the concrete from wicking into the timbers as it cures. This slab is 9 feet above the basement slab - I don't think water will wick up 9 feet from the basement and rot these white oak timbers. If it does, I might be the fool I pitied in the previous sentence. :)

*the trapezoidal 2x4 structure in the form work is a form itself. It allowed us to recess the slab 1.5" into the main slab. This is so the firebrick in my hearth will be at eactly the same level as my finished floor. My original idea was to block out this space with something that would displace the concrete. My b-i-l knew better though. The problem with using a solid form to block out something like this is that it's darn near impossbile to evacuate all of the air bubbles from beneath a horizontal concrete form. I wanted a smooth level surface to lay my firebricks on, so we went with his idea. About an hour after pouring the concrete, it was firm enough that we could scoop out 1.5" of concrete from inside of the trapeziodal forms.

* in the middle of the trapezoidal 2x4's is a foam block out that will be removed after the concrete cures. It is the size of a single 4.5x9" firebrick. This opening can function as a fresh-air make-up to the fireplace, and as an ash dump. The 2x4 across the top of this foam block out is to keep it from floating while the concrete is wet.

* there is another foam blockout to the left of the trapezoid. it is for a flue that will allow me to put a furnace or hot-water heater in the basement and vent it through the chimney - if I should ever decide to do so.

*water bottles on the rebar are to keep us from accidentally cutting ourselves. (whoops, some were removed when I took these pictures!) That stuff is very sharp after being cut with an abrasive chop saw. A person would be well advised to cover vertical ends of rebar with something even more substantial.

New mascot for the house project

On the way to the house site the other day, I noticed a large black lump in the road. At first I thought it might be a feral black cat that often hunts mice in the field below our house. But as I approached the animal, it didn't jump away - instead it barely took notice of me.

It was a huge snapping turtle. No, the irony was not lost upon me... surely this was a sign that I have been taking too long building this house. This beast was out of his element, taking his time getting to where he was going, and not letting anyone get in his way. What an inspiration!