Maybe “tutorial” is too strong a word. There will be pictorial or drawing examples of each type of job required to finish a house that I am either involved in or privileged to photograph. It is by no means an exhaustive handbook of the type you get when you take the Habitat Crew Chief and SPM training course. The intention is to try to document real-life on the slab, including the good, the bad, and the ugly. Fortunately, it all turns out good.
This is the second part of a multi-part outline of what is involved in building a Habitat house. The first part is Habitat Tutorial – Prepration for Build. In addition, there are two sets of pictures with slide shows that have already been published that you may be interested in as they concentrate on people on the job site – volunteers. The first is Habitat for Humanity – 2008 Dinner on the Slab consisting of 25 pictures including our future homeowner Nicole Combs and her son Elijah. The second includes 115 pictures of the first day of the build – Habitat Build 2008 – First Day – Walls Go UP .
Note: If you came here looking for the homeless veterans site, this is it! If you came here looking for the homeless youth site, this is it!. I’m just taking a break to help out on a Habitat House and once a year I post what I saw, experienced and learned. Click on either of the two links in this paragraph or go to the side bar and select a category or search for what you want. Also look above the banner or to the right for popular articles on Homeless Veterans.
In the earlier tutorial I showed the plate markings. These two boards representing the top and bottom plates of a section of a wall are tacked together and left lying somewhere on the slab. All a volunteer has to do is separate the plates, remove the tack nails and insert studs, T’s, window or door frames and nail them up.
You can see in this picture a stack of top/bottom plates on the floor on the right, a separated set being stocked in the left foreground and one well on the way on the other side of the slab. A set of blueprints are laid out on the slab on the right, but it is seldom needed as the slab is already carefully marked with all the walls, doors, etc. and the sets of plates are numbered to match. The rod with the orange ball on top is the future grounding rod for the electrician. We will notch a wall to fit around it and around the various plumbing pipes (such as the blue pipe with the white top in the far right. The shadow on the slab at the bottom left is all you are going to see of me!
Before the walls go up, the walls receive a “Sill Seal” (the blue polystyrene strip shown partially loose on the bottom of the wall). The bottom all the exterior walls receive this sill seal to help seal out any air leaks. The corrugated side of the seal goes to the slab. The Sill seal is attached with roofing nails placed every 24 inches.
This one is loose because it was discovered that the notch for the electrical grounding rod would land on one of the studs. The sill seal was loosened and the stud removed (the one laying at an angle) and will be relocated slightly. Notchs are cut before the walls are installed.
This notch is bigger than needed because the first cut was not quite in the right place. Notches are cut with the wall on the ground with a skill saw with two cuts from the edge, then knocked out with a hammer or a chisel if handy. It is easier to get it right if the wall is lifted into place first, then marked, but this was a long wall so the position was calculated and slightly off. In the end, the wall was lifted twice anyway. You can see the top of “cut nails” in between the studs.
These are notches cut out for the plumbing wall. Plumbing walls are double walls and fit against the plumbing T shown in the first tutorial. Notches don’t have to be pretty but should leave some wood for nailing to the concrete to stabilize the studs. If necessary, the studs are relocated, and sometimes if a very short bottom plate is left after a big notch, a connecting board runs from one wall to the other to stabilize the hanging stud.
This is a plumbing wall installed. It may not be the same wall as shown above, or the notches may have been cut all the way through. See the cut nails in the blocks to keep the studs from moving on the two that are cut all the way through. The larger white pipes will be cut off by the plumber for the toilet drain. The mid size pipes are for sink drains and the blue wrapped pipes are cold water and the red marked ones for hot water. It appears that someone is already marking stud locations on the concrete.
Hurricane straps are buried in the concrete and the ends left sticking up for use to hold down the walls. I’m talking about the shiny strips hanging out of the wall at the bottom of the picture and also off the left side. There is one on each side of the board at every location spaced about 4 feet apart.
Every strap is bent tightly over the board and nailed, one to each side and 3 in each top. The top nails are angled so they don’t hit the concrete. 8d nails are used here. The straps are used to keep the walls from being easily lifted or pushed off the slab during high winds. There are similar straps used at the tops of the walls to keep the roof trusses attached so that the entire house is locked down to the slab.
This is a “cut nail”. It is very hard and can be easily driven into concrete. Safety goggles must be worn by anyone nearby when driving cut nails as they typically do not bend but break instead. The edges are sharp enough to produce cuts on the skin if handled roughly so be careful. The name comes from the way the nails are made. They are stamped out (cut out) of sheet metal then hardened, whereas our other nails are cut and formed from wire rolls. OK, a little more of me got into this picture.
This is not the optimum hammer for driving cut nails but it is heavy enough to do the job. There were a number of volunteers at work doing this job. A cut nail goes into each gap between studs. In this case this is a door opening so the nail goes into the space where the jack will sit on top of it. Some end up in the middle of doorways where they are knocked out later – unavoidable when volunteers get ahead of instructions. The nails are oriented to run with the grain to avoid splitting the wood.
Here is a standing wall section, typical for those on the site. Shown is a window unit in the middle with a wall brace running to a stake in the ground outside. To the right is a wall T for the connecting wall running to the back and an adjoining door. The wall T is oriented with the spacer to the back. To the left is a wall T waiting for an interior wall to butt against it, with the spacer oriented to the front. The walls are joined by nailing from the backside of the T into the end of the wall that runs up against it. Running sections of walls are joined by nailing through the studs that make up the ends of the walls. An example is the double stud to the left of the window. This is two wall sections joined together. A cap rail will be added to cap the wall which will span the wall end junctions so that they are firmly locked together.
If the walls are centered on the T’s they will eventually be perfectly vertical once the outside walls are straightened. Never straighten an inside wall until all the outside walls are done as the walls will straighten naturally if they are attached properly to the T’s. Notice the spacing on the cripples below the window. They are spaced on 16″ centers with the adjoining studs and not just based on the window opening. This provides uniform nailing points for the drywall and external sheathing. There is an extra cripple on the right to get the spacing right. Notice the hurricane straps about every 4 feet. Notice the one on the far left is nailed up the side of the T rather than attempting to nail through the small opening which already has a strap. This is OK.
Here are some interior walls stacked around waiting for installation. At some point the outside walls will be completed. It is nice to have all the inside walls on the slab so that no wall is required to be lifted over the top of an exterior wall. Even so, one wall ended up locked outside and had to be lifted over.
Walls leaning against walls is one of the reasons for carefully bracing the walls with angled braces. Also tired volunteers may decide to lean against a wall. We don’t want it falling over with him/her on top of someone trapped outside. Notice the one wall with a strip tacked across near the bottom. This is temporary to stabilize the sections cut out for plumbing.
This photo illustrates stud marking. Volunteers mark the location of every stud on the slab and on the cap plate of every wall, including the outside edge of the slab. The intent is to make it easier to find the studs when the outside sheathing is going on and when the drywall is going on or up.
Here the cap plate is going on the top plate of the wall. The cap plate ties walls together and straightens every joint. They must bridge the ends of wall sections by at least 4 feet and they should aways end on a stud. Cap plates should extend into a wall it butts into. In the case above the 4 foot rule will be violated as the adjoining wall is closer then 4 feet. The portion under his hand will be cut away to allow the cap plate from the adjoining wall to come through (someone, out of the picture, got ahead of himself?). Is OK, can be fixed.
Here is the cap plate properly installed. It is the same spot. The cap plate at the right was carefully cut to make room for the piece coming from the other wall. Notice that the adjoining wall is tied to the running wall by overlapping the running wall top plate. This prevents any movement of the two walls even in the worst of conditions.
Here are two ladder headers for interior non-load bearing walls. One runs to the hallway from a bedroom and the other into the master bath. These differ from the drawing in my first tutorial as the wall serves as the header instead of the two by four illustrated in the drawing. Notice the inside of the T to the left to catch the hall wall. Nails are through the block to the end stud of the wall. Notice the wider plumbing T through the doorway to the right. Two walls will be placed on the plumbing T to make a 7″ wide space for piping. There are other walls still stacked around in the back ground.
The “41 LDR HDR” means build a ladder header 41 inches wide. 1.5″ wide Jack posts will go on each side of this frame reducing the space to 38 inches. Then the interior door frame is made of two 3/4 inch wide boards reducing it again to 36.5 inches. This leaves 1/2 inch clearance for aligning the door frame for a 36″ door. Exterior doors headers are 41.5 inches wide to allow for the thicker door frames and the exterior headers are 10 inch wide boards spaced with a 1/2 inch plywood spacer instead of the cripples shown.
Debbie is installing metal strips that catch the OSB 4×8 sheets to be installed shortly. The top of the metal strip is aligned with the top of the 2x4s. The OSB rests in the J section in the bottom of the strip. the strip fits closely against the 2×4 base plate and drops below it helping to seal the junction between teh plate and the concrete from windblown water. The outside siding to be added later falls below this strip so no water collects anywhere it is not supposed to. There is already a crew installing the OSB behind her, out of the picture.
OSB stands for “Oriented Strand Board”. It is the pressed wood chip boards that are so commonly used today. The chips are placed more or less randomly but intentionally oriented to straighten the board in all directions then bonded together with an adhesive resin. This manufactured sheet has the chips oriented one way on the outside and crosswise on the inside though a sifting process on the assembly line. This is not left over pressed sawdust but instead is carefully engineered water resistant manufactured wood.
This is what OSB looks like (per copy from Wikipedia) before it is pressed. Notice the slight change in color near the middle third of the board where the chip orientation is different. The board is incredibly strong.
Steve and others are installing the OSB. The edges are nailed with 8d nails on 6 inch centers on all edges and 12 inch centers on the studs in the middle of the field. Studs are marked on the slab beforehand with magic markers and a level is used to draw vertical lines for nailing in the fields. Some OSB comes marked with the lines already drawn and a few experienced volunteers can find unmarked studs like radar.
It is necessary to remember that there are window or door openings and allow for nailing on 6 inch centers around those openings. Notice the insulation showing in the T’s.
Earlier we had to build an extra window frame because somehow we were short one (in another wall). Later Nicole asked why there was no door leading outside the kitchen. Oops, there was the missing window frame where a door should have gone. The rouge window was removed. In this picture the nails are still in place. These were cut off with a metal cutting blade in a saws-all. The extra door was still sitting on the ground outside (which should have been a clue). We are all standing around guarding the opening so no one steps on the nails while the saw if found.
Here Jeff positions the new door while Terry takes early advantage of the new opening. The window at the left was originally built the same as the others, then shortened to a kitchen window so it would fit over the counter top and sink. Additional Jacks and cripples made it easy. Notice the plumbing in front of it.
Here the sill plate is being cut out. The skill saw base plate is 1.5 inches wide so it is easy to use the stud as a guide. The jack post that goes next to the stud is already ready to be put in. It rests on the 1.5 inch piece remaining. The saw blade is adjusted carefully so that it does not quite touch the concrete and the bottom board leveraged up to get it out. Any cut nails in the concrete are loosed by hammer blows to the board beside them and they usually come up with the board or are broken off flush with the concrete. Any remains are driven in. A saws-all can do the job as well, but is harder to get a perfect cut.
An old chisel is used to remove the remaining bits of wood after the sill is cut out with a skill saw.
Here the porch beam is being constructed (long boards in the foreground) while others finish up the OSB siding and stil others prepare the house for straightening the walls. Notice the block of wood at the top right corner. More about that later. Notice that all the walls are up and capped and many of the braces appear to be removed. Actually they have been moved inside and positioned so the walls can be braced in new positions that keep the walls perfectly straight all around.
This is a view of the short end of the porch beam already in its “pocket”. The components of the porch beam includes the two sides and the one across the front. The beams are 2x10s with a 1/2 inch plywood sandwiched inside and well nailed together.
This is the other (longer side) of the porch beam side rails as it is being shoved into its pocket. There are 2×4 boards being readied for temporary outside support. Notice that the beam extends inside the house and into a built in pocket sized to keep it locked in place and stable.
Nailing the porch beam in place.
The beam must be absolutely level! Vertical braces are nailed on to the outside of the beam to stabilize it and supporting jacks nailed onto that. The beam must support the roof trusses as they are hoisted up later without moving.
This beam was cut a little short when it was first made, a mix up in communications between the guy measuring and the guy cutting. One was measuring between the inside of the outer boards on the side beams and the other cutting to the end of the outside beam. The result was a front beam that was 3.5 inches short. The front beam should lie across the side beams but was adjusted to fit to the inside of the side beams due to the measurement problem. 1/2 inch spacers were used to make up the difference. One result of all this is that the front overhang is a little wider than normal and the posts will sit a little closer to the house. No real harm done and a couple of expensive boards saved.
These fellows are installing “dead wood a.k.a. deadwood”. On the ends of the house where the trusses run parallel to the house, the deadwood serves the purpose of giving a place to nail the edge of the roof truss to the frame of the house. Deadwood also serves the purpose of providing a nailing strip for the ceiling drywall on that those ends of the house. The dead wood is a 2×4 board positioned so that it overhangs the room below. It is spaced from the edge of the wall by holding a short 2×4 board edgewise on the top outside edge of the cap plate. See the picture above. This spaces the board over by 1.5 inches giving a 2 inch nailing space on the cap plate and a 1.5 inch overhang that can be used to nail the ceiling drywall to..
The 1.5 inch wide roof truss fits down the outside (this side) of the dead wood and onto the cap plate so that the roof truss is in the same plane as the frame before the OSB goes on. OSB also goes on the outside of the roof truss so that it all fits correctly. The roof trusses are nailed directly to the deadwood and also toenailed to the frame.
Well, after writing all that, I figured I was confusing any novice that came along so I created this drawing to illustrate what is going on. The Wall stud, top plate, cap plate and the wall sheathing are all existing. The edge of a 2×4 block is placed where the future roof truss will go and a 2×4 board is nailed onto the top plate as illustrated. Later when the truss goes up, the bottom edge will be nailed to this dead wood and even later when the drywall goes up, the drywall will be nailed to the bottom edge of the overhanging deadwood.
Travis shows the proper offset technique.
This is one end of the setup for straightening the walls. There is a block like this at each end and a very tightly strung line. The line goes over a nail on the far side and then is wrapped around a nail as shown so that the line does not need to be cut. It will be moved around and used on each outside wall. Generally the longest wall is done first.
This work is easiest done from the inside. A board is moved along the wall inside of the string. Any variation in the wall will show as a gap or a bowed out line. Volunteers inside move 2×4 boards attached to a stud near the top of the wall pull or push the board until the board barely touches the line and then nail the board near the bottom of an adjacent wall or along the side of a butting wall, always at an angle sloping down. When done with all the walls, the walls will be perfectly steady and vertical throughout the house. Interior walls will generally be straightened as the outside walls are brought into plumb.
The board angling down on the right is a temporary cross brace that holds the outside wall perfectly vertical. It stays up until the roof trusses and decking are on. Notice the dead wood overhanging the cap plate on this wall.
When there are large areas with no interior walls to brace along or against, blocks of wood are cut nailed into the floor and wall braces attached to them. The technique is to first attach near the top of the wall and then push/pull until the wall is straight using the pole and then nailing the pole to the side of the block on the floor. The man on the ladder is calling out instructions to push or pull.
In most cases the windows are covered in OSB and cut out later. Here a saws-all is used to cut around the inside of the frame. A hole is started somewhere with a drill or through a gap in the wood or with the tip of the saws-all. Cut a long arc to get to another edge then back track to cut the arc out.
This picture shows several things. Notice that a top plate and cap plate have been added to the porch beam. Also deadwood has been added to the cap plate at the front. The porch roof truss will be set in front of the deadwood (on the other side of the beam as shown). Also notice the supports attached to stabilize the porch beam includes an angled 2×4 to keep it from twisting.
The tall pole at the side of the house is a very sturdy safety brace that will temporarily support the roof trusses as they go up. The first roof truss will be hoisted up using long forked poles over the front of the house and slid back to be parallel with the side with the pole. Then it will be lifted up and leaned against the pole and dropped into the pocket behind the deadwood. Volunteers with ladders outside will nail the truss to the deadwood and to the top of the tall pole. The following trusses will be nailed at the ends of the walls and tied to the first truss with temporary boards running across the tops of the trusses. The tall pole is a safety device as the trusses can easily fall over until the roof decking is up and the trusses cross braced underneath. The trusses are heavy enough that even one can severely injure someone and when they all fall over it can be deadly to several.
Here is an inside view of the safety pole. The piece of OSB attached near the top serves the purpose of matching the plane of the OSB on the bottom wall so that when the truss goes up, it will be vertical when it rests against the OSB on the pole. The first truss will be firmly attached to the pole.
Here a temporary walk beam has been added over the living area. It fits into a pocket at each end made up of a double jack below the beam and a 2×4 on the other side of the beam, locking it in. The pocket is built at both ends and an extra support added in the middle and attached to the floor. The beam is made of two 2×10’s with overlapping boards to get extra length. This beam serves the purpose of giving the roof trusses a place to rest as they are hoisted over the front wall.
The trusses are long enough to reach past each end of the house and as they go over the wall they can get overbalanced and fall in and fall on someone or scoot along the floor and possibly injure someone. The beam holds that end up temporarily to allow the truss to rest and slide easily to the back. The roof trusses are also shaped like an “A” and so even when they are completely across the house, the heavy top of the A can cause one to tip over and the top of the truss rotate and fall into the house. The walk beam prevents that from happening too. It is a sturdy safety device. It will be removed after the roof is fully stabilized.
A good day’s work! The house is ready for a roof! Saturday May 17, 2008. See your there?
(corrections gratefully accepted)