Tuesday, December 29, 2009

Week Nine Update - Rainscreens

The cedar siding started going up yesterday. I've been looking forward to this so I can get a better vision of how the outside colors will work together. Having the cedar boards in place will help me select the color of the stone for the chimney and the paint color on the brick. The paint color can wait a while but I'd rather go ahead and make that decision with the stone choice.

The cedar is being applied over a "rain screen" product that is a hard, yellow, plastic mesh. This mesh will provide a layer of air to circulate behind the cedar. Any water that penetrates the boards or joints will gravitate through this zone to the ground below. The primary layer of water protection is the Tyvek and flashings that cover the wall. This airspace should greatly lengthen the life of the cedar as well.

You will see rain screens being used more frequently. The theory is that the visible exterior skin is in place specifically to block some of the precipitation and all of the sun - nature's primary tools of destruction. The interior layer of a building's exterior wall includes the final layer of waterproofing (Tyvek and flashing), the structure, thermal blanket, and the interior finish surface.

The idea for a rainscreen is that this open space allows air to circulate and moisture to escape from behind the outer skin. If the moisture is trapped behind the outer layer (regardless of the material), it will do some very bad things. Moisture will expand when it freezes and slowly delaminate a wall. Moisture inside a wall can also create mold which will cause rot and health issues.

An example of this failure can be found in the first buildings to use EIFS (exterior insulation finish system) back in the early 80's. EIFS was also called by its proprietary name - Dryvit. This product became popular because you could glue rigid insulation foam over the outside of any hard wall and coat it with a stucco material. It was fairly easy to install, gave you great insulation values and you could cut it to any shape you could imagine.

However, what began to occur with poor installations was that water would find its way into the joints and freezing temperatures would pop the insulation off. The product got a bad name and was actually banned in North Carolina - until a rainscreen system was created to drain any wayward water out from behind the outer insulation layer.

Brick veneer walls usually behave as rainscreens. Brick is a porous material and water will easily wick through it. To rid the water that migrates through the brick, there is an airspace of 1-2" to let migrating water run down the inside face of the brick. This only works when there is a way for the water to escape through "weep" holes at the bottom of this cavity.

Rainscreen materials may vary, but the concept is the same.

Saturday, December 26, 2009

Start of Week Nine

It's the Saturday after Christmas and the 50+ degree rain last night melted most of the snow. The only snow that remains are small piles where the roads were scraped.

As you can see from the photo, my daughter Ashley decided to get into the house-building business and made me a gingerbread house for Christmas. It's very cute and almost to scale - even simulated the important features such as the beams and windows. I wonder if the contractor will let me make a few late changes - cedar siding to gingerbread and the copper panels to Twizzlers? Probably not.

Today was our electrical walk-through. It was necessarily long (2 1/2 hours) and methodical. I've been anxious about this as I haven't had enough time with Carrie to review the many light fixtures that I've culled through. We also don't have prices from the distributer who will likely be supplying a lot of them. After I revise the fixture list this weekend, I'll be submitting that for the supplier's review.

Our house is not large, but the open/taller spaces provide an opportunity (read: challenge) to play off the architectural character. The upstairs walk-through took well over an hour but it is the hardest space to light since the ceilings are tall and have sloped ceilings and exposed beams. The challenge there is to gently light the ceiling, create a few hot spots on the floor, and wash light across the walls where art is likely to be placed. Doing this without creating a distracting clutter takes some consideration.

I also hesitate inserting any recessed fixtures into the insulated joist space. This would create another thermal break in the insulation and potentially create a condensation issue at the point where the hot fixture meets the cold from the outside. The solution seems to be track lighting dropped from the beams and smaller lights that can be flexed after installation.

The most unusual light fixture we have selected is over the dining room table. Instead of the usual pendant, we have chosen an 8' flexible track with 5 suspended lights. It is by design flexible and must be composed in the field. We'll also use a couple of these lights as pendants over the counter between the dining room and the kitchen.

One thing that has always puzzled me is how a three-way switch gets its name. I probably need to have one of our electrical engineers at work explain. A three-way switch has two switches that each connect to the same light fixture(s). A house will usually have a few of these - most often found in rooms that have a door to the outside. In locating lights and switches during rough framing, you have to figure out how each room will be used and where the furniture will be.

Now that the lighting and electrical is mostly behind us, the electrical sub can now begin wiring rough-in. Next up for me will be to design the stair and various railings. Carrie and I will also need to start selecting bathroom tile, kitchen backsplash, granite countertops, and the stone that will face the fireplace. That will keep us busy for a while.

Wednesday, December 23, 2009

Mechanical Installation

With the snow hanging around this week, the most visible activity is taking place inside the house. The mechanical and plumbing contractor installed the downstairs furnace at the bottom of the stair to the basement. With an 84" height down there, they are keeping it the ductwork inside the joist space where they can. One little detail that Carrie noticed is that the openings for the first floor vents are covered. This will help keep construction debris and dust out of the ductwork during construction.

The basement was tested for Radon and as expected, it showed a high level - enough to warrant a mitigation system. We knew this after a letter showed up 6 months after we moved in - from a company who had performed a Radon test for the previous owners. The letter stated that high levels had been found and wanted to know if we wanted them to do the work that the previous owners had elected not to do. This should have been revealed to us at the time of purchase. Maybe I'll send their real estate agent the bill.

Radon is a radioactive gas that comes from the ground and is touted to be the second-leading cause of lung cancer. It can be pulled out of the ground through cracks and joints in concrete walls - essentially sucked out of the earth by the negative pressure that exists in most houses. You can find some useful information on the EPA website: http://www.epa.gov/radon/pubs/consguid.html#overview

There are simple methods to remove it from crawl spaces, slabs, and basements. The ususal one is "soil suction" - like the one being installed in our basement. As I understand it, a hole is drilled through the slab into the ground. You stick a sealed PVC pipe over the hole and try to pull air from the ground with a fan. This air is vented directly to the outside. Because our basement does not have a porous stone base under the slab -but was built directly on compacted earth, it means we need three holes instead of one. This system should become the conduit for the gas to escape. Hope it works.

At lunch on Tuesday, I walked around with Michael and Todd to determine where blocking and other framing will be needed prior to the electrical rough-in for items to be mounted on the wall like towel racks and toilet paper dispensers. The blocking will provide a screw-able surface and stiffen the wall.

We earlier had discussed a stategy for the mechanical duct around the top of the second floor ceiling - but elected to hold off a final decision until we could be in the space. I'm glad we deferred that as there are a couple tweaks that will make those taller spaces work better. Normally, I would have wanted to minimize the soffit height below the ductwork. However in this case, dropping it in the bedroom to line up with the window bay makes the most sense. It will also provide me a nice place to pocket the shading treatment and LED lights for the window bay. I should also be able to now get the glass panels above the closets between the bedroom and the den - making the exposed beams on the second floor more visible.

A rainstorm is expected on Christmas day. Maybe that will melt some of this snow and let them start working on the siding.

Saturday, December 19, 2009

Start of Week Eight

Timing is everything. I could get paranoid about the record-wet weather we've had since construction started in early November. Instead, I feel lucky right now that the house is dried-in and the work done won't suffer any negative affects from an unusually heavy snowfall for this area and time of year.

This morning was to be our electrical walk-through but there was no way that was going to happen with so many roads impassible. I was able to trudge the half-mile from our rental house to the construction site. It was a quiet walk right down the middle of the road - following in the wheel tracks of the few nuts who couldn't stay home. There were many people out socializing and shoveling snow - trying to free their cars and clear sidewalks while the snow was wet.

I spent almost 2 hours at the house trying to visualize some of the spaces and thinking through some of the details that are unresolved. These details include the rail design, HVAC framing, and lighting. It was great to just sit in the various framed spaces and visualize how it will be when closed up. It is now easier to decide where to throw light, put switches, and place furniture. I also noticed a few things that I'd like to tweak - one regarding the refrigerator depth, a change in strategy about lighting the living room, and another that has to do with the rail at the top of the stair. It's a good time to be noticing these things.

Overall, I am very happy with how the interior space works. It will be a wide open house that is filled with light during the day. The architecture certainly has a point-of-view, but when the materials on the outside are applied (and the white Tyvek is covered by the cedar), the house should pull back into the landscape more. This will continue over time when materials like the copper panels get their brown patina.

This week's homework will be mostly about getting ready for the rescheduled electrical walk-through. With this extra week and the chance to spend some "quality time" in the house, I can now coordinate the lighting cut-sheets with the plan. Carrie and I will also have more time to get on the same page.

Tuesday, December 15, 2009

Week Seven Update

There has been a lot of visible progress over the last couple days. The windows and front door are now in place - which give the structure a more recognizable scale. On the inside, much of the framing is up and a temporary stair is set, allowing easier access to the second floor.

Being up on the second level will help me visualize how the lighting might work - particularly in those taller spaces with the exposed beams at the roof-line. Saturday will be our walk-through with the electrical contractor to review the electrical plan. It always amazes me how many things you need to think about to turn on the lights.

It is my desire to keep the lighting out of the ceiling cavity to maximize the effectiveness of the insulation. To do this, we'll be using pendants mounted to the ceiling surface and track suspended from the beams. The track will have lights that can be directed to throw light on the tall wall surfaces or bounce softer light off of the ceiling.

There are many decisions to be made at this point. This weekend, we finalized all of our pluming except for a pedistal sink and a vanity bowl. Today, I looked at 3 samples of finishes on the cedar siding. Up close, there was a noticable difference but from the street two of them seemed very similar. The same thing happened with the finish samples on the glue lam. I decided to use the redder, slightly darker stain on the siding so there will be less contrast with the dark windows frames. The red tint should provide some color too.

With the windows in place and all exterior surfaces insulated and covered with Tyvek, the cedar siding can now go up. That layer will really add some texture to the house. The contractor will start back-priming the cedar boards before they go up. This prime coat will coat the siding in all those areas that aren't visible and protect it from moisture that may get trapped inside the wall.

One other decision was to select the metal roof and metal fascia color - a medium bronze. This was a hard call for me. The roof over the living room and garage are minimally visible from the south so I elected to use a metal pan. Ideally, the material would be copper to match the panels directly under the overhangs. However, the copper will turn to brown within a year so all that expense would be lost on a large area of roof that is minimally visible. The medium bronze will hopefully match the copper once it ages.

At lunch today, I visited a company called Tektonics Design Group which is a creative studio and fabrication shop. They do every kind of design from metal connections to houses. Baskervill has been working with them on some specialty items that are really cool. My thinking is that they will be able to develop my thoughts on the stair and guardrail and then fabricate the items as well.

They will also take a look at bookshelves in the living room and a horizontal cover over the entry door. The bookshelves will be an important feature on this very tall (14') wall. My initial thought is to have them as a 9' "broken" grid of 18" square shelves. Perhaps Tektonics will take my concept to a more interesting solution.

Another detail that I'm getting them to take a look at is a horizontal "blade" of copper that could go above the front door. Because the roof overhang is so high above the entry porch, this item may be useful during a rainstorm from the south. Aesthetically, it will provide a protruding a horizontal line that is counter to the vertical windows that are around it.

I'll post some pictures on Wednesday after a visit at lunch tomorrow. I'm giving a quick tour to a couple co-workers who helped me at various points along the way.

Friday, December 11, 2009

Week 7

Most of the exterior framing was completed this week and the windows are now being put into place. You can now see the final form being revealed. Other items that were done this week are the placement of copper end-caps on the front glue lams and closed-cell sprayed insulation between the furring strips on the front wall. The basement stair and the temporary stair to the second floor will be set on Monday.

I asked the contractor to give me more time to design the stair and rails. These are very visible elements in the design and what I had started earlier just didn't make me happy. With Virginia's 4" rule for railing openings, the vertical pickets were just too opaque and at the balcony further accentuated the vertical character of the living room. They also hinted of a traditional design that was found nowhere else in the house. Instead, I am working on a design that is held up with thin darkly-painted thin metal posts and horizontal rods spaced at 4" centers. Wood will cap the rail.

I'm very happy with the way the glass bay on the front corner breaks up this otherwise flat facade. It appears delicate in contrast to the opaque walls around it - almost floating. This bay is very visible as you come up the steep hill after going under the railroad bridge.

The windows are from Jeld Wen, have high-performing glass with Low-E coating, and are filled with argon gas. This should be a huge improvement to what was there before.

I can't say that the house is completely designed to be passive solar, but I tried to balance the desire for views, light control, and heat loss. Here is my strategy for controling the sunlight and heat-gain in the house:

1. There is minimal window glazing on the west and north sides. The north side usually would provide the best quality of light, but on this property the north side is highly shaded and faces the neighbor's garage. At least the dense trees and fence help block the cold north winds.

2. The west side of the house where the evening sun is low and hot in the summer also has a limited number of windows. This elevation benefits from a key element of passive solar - deciduous trees. In summer, the large oaks will shade the house from the heat gain that comes from the low sun. In the winter, the leaves are gone and the afternoon light helps heat the house.

3. The south side is usually the key for successful passive solar design. South orientation benefits from a high midday summer sun that is easily shaded by overhangs. In the winter when the sun is much lower, the light can come into windows and heat the interior. Because the long dimension of the old house was running north/south, the best passive opportunities were limited. What I did however was to put some windows with large overhangs over the garage roof. This will bring light deep into the open part of the house - reducing the need for electric lights in the daytime. The south-facing glass at the entry is also shaded from the afternoon sun.

4. The east elevation has a lot of glass - contrary to normal guidelines for passive solar design. All this glass is there to maximize the primary value of the location - the long views of the river. To me, the morning sun on this side is not a big problem since the heat gain is minimal due to the low sun-angle and the very large overhang. Because our house sits so high over the river, we have a direct view of the east horizon. It is a real treat to wake up to the red glow of the morning sunrise.

At some point in the future, I expect to put PV solar panels on the garage roof. They would not be too conspicuous in this location. The orientation is correct and there are no trees in the neighbor's yard to block the sun. The roof angle may be flatter than desired, but when the technology and cost make sense we are ready.

Tuesday, December 8, 2009

Week Six Update

From the time this image was taken till the end of the day, the framers finished the roof. This includes near-flat roof at the back and the section over the porch. This porch used to be our sunroom and may one day be that again. For now it will stay a covered porch.
This image shows the thickened chimney - with block added onto the side so it will match the thickness and symmetry on the inside. It will be covered with thin-stone.

There was one more (hopefully final) surprise today. This one became apparent when the back sloped roof was pulled off, revealing the block under the old trim. The drawings had anticipated finding brick there but the original builders used one row of block to save a couple 1954 dollars.

That detail now creates a decision for me. Do we replace the block with brick which will then be painted with the rest of the wall, or do we put a trim board over it. The latter is cheaper and might look just fine.

It is getting much easier to understand the volume which will be the living room. The front (tall) window is now framed in. To me, this is the most important, but undesigned room in the house. This room is most important because this is where all the special details and materials are seen - wood beams, unique windows, fireplace, balcony railings, and kitchen.

The more I see this room, the more important that the fireplace wall becomes. My original and current thought is to put a grid of bookshelves on either side of the fireplace - up to a 9' or 10' height. With the height of that wall, it will be important to use these as a design feature to humanize the 14' height. They should match either the height of the adjacent window or the ceiling line under the balcony. Pulling from one of these lines will help unify the space. The budget may delay this for the time-being.

It would be very dramatic to put the chimney stone on the inside face of the fireplace wall - all the way up to the ceiling. The wood ceiling beams will then frame either side.

I'm starting to realize just how many decisions are still to be made - and some design tweaks that I'm finding now that I see the space. Architects have an enhanced ability to understand theoretical space, but there's nothing quite like being in the actual built space to really see how space is connected and how the details intersect.

Saturday, December 5, 2009

Week 6

It's a rainy Saturday and I've included a few new images of the house. The outside is starting to show its overall form though it's hard to tell with all the tarps that cover everything. The contractor has done a nice job of keeping everything dry during all the rainstorms. They button everything up at the end of each day.

Before much longer, it won't matter how much it rains or snows. The adhered TPO (membrane) roof is being installed above the second floor and the window installation will start soon. The high roofs are not seen from any angle and will be white. This is a very reliable roof and the light color will reflect the hot sun we get during the summer. This will hopefully reduce our airconditioning load.

The windows are sitting at Siewers Lumber and are made by Jeld Wen. The exterior is aluminum clad and will be a color called Chestnut Bronze. They will appear to be very dark in color with a hint of brown. Hopefully, they will provide a nice contrast to the warmness of the natural cedar siding that will be around the largest areas of windows. They are high-performance windows and will be a huge step-up in performance from the 50-year old single-glazed aluminum ones that were in the old house. We will apply for the $1500 federal tax credit that is out there for window upgrades.

There are a couple things that I am working on this weekend to stay ahead of the contractor - the electrical plan we'll use for the electrical walk-around and the stair design. The contractor created an electrical plan to use for pricing purposes but it needs to be reworked to fit our actual wishes. I met with a lighting designer who used to work at Baskervill. Her firm will provide the specialty light fixtures - those that are visible or have special features.

Some of the lighting concepts that I'm working around are to (1) keep the ceilings with the open wood framing as uncluttered as possible (2) use light to emphasize the character of the design, (3) find a balance between privacy and the outward views, and (4) avoid recessed lighting into the insulation spaces.

The contractor had given the millwork shop the go-ahead for the stairs based on the direction I was going last time on the railings. Since that time, I've had time to draw and feel the space in the living room. It is now my feeling that a verticle "picket-type" rail will add one more vertical element to an already tall space. With the contemporary nature of the design, it also seems that a horizontal rail is more appropriate. I asked the contractor to put a hold on the stair to the second floor until after the weekend where I could try a different concept. They will continue to build the stair to the basement - which will help them access the MEP systems that will be down there.

Yesterday was my first time up on the second floor. I had to climb a ladder from the living room that was leaning against the second floor balcony framing. It's not something I would do without another person bracing the bottom. The views are as cool as I had expected. A great deal of the river is visible and from the large bedroom bay, the Carillon tower in Byrd Park is framed nicely between the two tall oaks.

My hope is that the tarps will be coming off soon and the images that I post of the exterior will be a little more revealing.

Tuesday, December 1, 2009

Roof Framing Goes Up Today

Here are some pics at 1:00 PM today. By the end of the day, they had completed 2/3 of the roof rafters that go on top of these glue lam beams. Rain is expected tomorrow again so they were buttoning it up overnight as I was picking up mail at 5:15.

They expect to finish the roof framing of this section and have it dried-in by the end of the week. Great progress considering we've had 9.6 inches of rain since they started in early November.