Silt Fences

Before I had any experience working in the field, I thought silt fences were just to keep top soil and other types of soil and aggregate from leaving the perimeter of the site. One day on the job site I asked the superintendent what exactly a silt fence was used for and he explained that silt fences weren't for containing soil on the site, but that was a side effect. Silt fences are predominantly used for protecting streams and other bodies of water. The synthetic liner(in black pictured above) guards from loose soil leaving the area during a heavy rain that could ultimately end up in the lake or stream.

To install a silt fence on the site, you want to keep the synthetic on the inside of the property, and the stakes on the outside, just as you can see in the photo above. Old school ways of putting up a silt fence involves first putting in your stakes. These are mostly wooden, but could be some type of composite metal. After the stake are set in the ground, you trench out an area of earth so that the silt fence can rest above and below the grade of the land. Then the liner is attached to the stakes. Once the liner is attached to the stakes, the excavated dirt can be filled back in and your silt fence is installed.

When I was looking up different methods of installing silt fences, I ran across the website. Burchland Manufacturing has created a plow like piece of equipment that speeds up the process of installing the material. The piece of equipment attaches to the front of a bobcat where it then plows and lays out the silt fence in one motion. The synthetic roll is attached on a peg and is rolled out into the trench after the plow on the machine tills up the area. The pictures below taken from their website where you can find more information regarding the the installation process and information about the equipment. http://www.burchlandmfg.com/silt_fence_installer.php .

House Wrap

What is the purpose of house wrap? House wrap is a protective synthetic membrane used to protect the outside of your home from moisture. It is just one more protective measure to ensure your home lasts for a long length of time. House wrap helps to prevent moisture from getting into the framing of a home and rotting out your sheathing and potentially the studs. It also helps to protect against mold and other related problems.

House wrap, if installed properly, can second as an air barrier. Either heat or cool air from the home will be sealed in and less likely to escape through your home since the house wrap is sealed against the building envelope.

House wrap was developed as an alternative to a tar based sealant for protecting the house. The synthetic material is much easier to apply and it goes up faster since it is lighter than applying tar. It is applied over the sheathing but behind the siding of the house.

A few key points that FEMA an the NAHB made were:

- house wrap is not supposed to be used as a vapor retarder. The purpose of house wrap is to let air pass through

-depending on the climate in which one lives, use a house wrap or building paper. Although they are similar, each one works well in their respective climates. The chart below taken from FEMA's website, explains in further detail when to use house wrap as opposed to building paper

-if the house wrap isn't installed correctly, then it could do more harm to your home and good. Water could become trapped and then potential mold growth or rotting could occur.

Trusses

The particular truss pictured above is a pre-manufactured truss used for a room. Trusses come in all shapes and uses if you decide to use prefab trusses as opposed to stick built. Conventional stick built trusses work just as well, it just depends on what type of roofing style you are going to use. Typically stick built trusses are most all of the time used when roof angles and pitches are not conventional, such as on a custom built home. That being said, these trusses can be used on regular pitched roofs as well, it just takes longer to build and set the trusses.

It also comes down to a money issue. Trusses that are prefab can be put up and set quicker, thus saving time. In the building business, TIME = MONEY. I would propose to use prefab trusses whenever possible because they help to save time. I haven't done a study on how much expensive trusses are than conventional stick built roof trusses, and it may come to a wash. Even so, if you can put up 2 more homes a year, or one more commercial project a year because of the time savings, you have already made more money. So from a monetary standpoint, it seems like a win/win situation. With the numbers I proposed, I was being quite conservative, so if the time savings are even more, then you have really done your business a favor.

There are all sorts of trusses available. There are trusses for putting air handlers in the attic, gable trusses, scissor - used for a vaulted ceiling, vaulted, shed, and the list continues on and on. Below is a picture, taken from http://www.raftertales.com/home-remodeling/roof-truss/, showing the many different options available with prefab trusses.

Also, below is another photo of a scissor truss in a set of plans we received over the summer for a home built in Roanoke. The scissor truss is in the family room. As you can tell, it creates a nice vaulted ceiling.

Soffit

The purpose of soffit is to reduce moisture in the attic and to also help to stabilize the temperature in the attic year round. Soffit is a plastic material with small holes that covers the outside extension of a roof, the eave. This allows moisture to dry through air flowing up the into the attic and out through the ridge vent. This photo is taken from class lectures.

It is important to regulate your attic temperatures throughout the year to extend the life of your roof. If you notice the gap between the wall section and the eave there is a gap. This is for the air to flow from the outside up into the attic. This is used to heat and cool the attic with the outside air. An attic acts as an oven in the summer times when attic temperatures reach more than 100+ in the summer months. Not only are your shingles being baked from the hot summer sun on the exterior, but the heat from the attic bakes the shingles from the inside as well. This causes the shingles on your home to wear faster than expected.

Flashing

Flashing helps to mitigate water from coming into the wall cavity. It acts as a barrier where moisture drains from. This particular area look as if there will be a break within different types of cladding. You can see where the brick ladder reinforcement is just above the flashing. The flashing will keep water from penetrating the break between the exterior cladding.

In class we learned about two different types of flashing. L and Z flashing. L flashing extrudes from the opening close to a 45 degree angle. Although this flashing doesn't have a 45 degree angle, it doesn't come straight down from the block on the wall. Z flashing comes out from the opening at a 90 degree angle. An example of Z flashing is below.

Another thing to take into consideration when dealing with wall cavities and flashing is that moisture has to have someway of escaping. In order for water to exit the wall cavity, weep holes are usually drilled at the bottom of wherever the cavity ends. Weep holes are pieces of small string that are bunched together. The soak up any moisture in the wall cavity and allow it to exit the building. The photo below shows an example of a weep hole.

Concrete Slab and Camber

After the concrete pour, this will be the stage of the elementary school at Prices fork. The steel reinforcement helps to strengthen the concrete. You can see the hangar bars that run horizontal on the left hand side where the rebar circles around. These bars are used to provide support for the rebar to "hang" on.

The way that the rebar is oriented on the left hand side is called an open loop system since the rebar does not make a full enclosed circle around the hangar rebar. If you notice, the rebar is held together at the cross sections with small pieces of rebar ties. These are similar to a twistie-tie you would find at the grocery store, but much more heavy duty. The rebar ties make sure the rebar doesn't move when the concrete is being poured.

The yellow material that you see on the top right hand of the photo is a vapor barrier. Vapor Barrier is a plastic lining used to keep moisture from entering the building envelope. Although this doesn't always stop moisture 100%, it does a good enough job to keep ENOUGH moisture out so that it won't effect the building. Although, if the vapor barrier is torn or defective before the pour, the material won't perform like it should, and chances of moisture entering the envelope are much higher.

One aspect that is not shown in this photo(because it is not a large enough area or supports enough weight) are cables, or tendons, in the concrete. These are more prevalent in parking garages where there is a lot of dead weight, but also high amounts of live load. These tendons can be stretched to create camber. Camber is the pulling of cables in the concrete so that the concrete "bows" slightly upwards once poured. When extra live load is added to the concrete with camber, it then settles to level as opposed to being level to start with and then being concave. The structural engineer will inform the contractor if there needs to be camber within in your concrete.

Once the concrete has been finished, the formwork(plywood material surrounding the stage area) will be removed and the concrete will be ready to go.

Power Float

**Power Float**

Although this picture is incredibly clustered with material, the power float in the picture was being used in a different area where the slab had just been recently poured. A power float is a machine that finishes concrete. The machine essentially has 3 or 4 trowels that spin around to smooth the concrete. As a result, a power float drastically speeds up the time to finish concrete. When using a power float, you want to make sure that the concrete has hardened enough to walk on. Bringing a heavy machine on concrete that is still wet would be disastrous.

To finish concrete, there are a few steps that take place. First, the concrete needs to be poured. Once poured inside your form, take a screed to level the concrete. This is called striking the concrete because of the "striking" motion one makes when pulling up the concrete and then leveling it with the 2x4.

Next, you use a hand float or a bull float(larger float on a pole so you can push longer distances). This is a "rough grade" for the concrete to become level. As you do this, water will come up because the mix is settling and the more dense mix is going to the bottom. **before you start finishing any concrete, you want to make sure to use a vibrator to "mix up" the concrete. The aggregate in the mix will tend to settle towards the bottom, thus, not creating an evenly distributed mix. The concrete will not be as strong as the specs called for as a result of the aggregate settling to the bottom.

**Bull Float**

Once you have bull floated the concrete, use the power float to finish the concrete. This is the "fine grade" on your slab. This makes the concrete especially smooth, taking out all the bumps and extrusions of the concrete. The opening picture for this blog post is a power float. Power floats come in 3 different types that I know of. 1)walk behind 2)ride-on 3)remote control. The pictures below are of each one, respectively. Once you are done with your finish float, the concrete is ready to go!

Remote control trowel taken from - http://famrichard.us/id16.html

Ride on power trowel photo taken from - http://cm.baumpub.com/news/507/multiquip-provides-versatile-ride-on-trowel

Bull float photo from - http://www.saltcreek.menard.k12.il.us/courtside_at_the_creek.htm

K- Joists

This engineered steel K-joist will eventually support a metal roofing deck. Most K-joists that you see are level and straight. Below is an example of what typical k-joists look like.

These joists, in the first photo, happen to be curved to fit the shape of the roof. K-joists in general are engineered, and can support heavy loads. They take the place of a stick built wood joist system.

The joists also have other applications other than just support. If you notice, they have a distinct shape within the two main beams, a triangle. This is so that conduit and other material can be run through the beams in the ceilings.

These joists do not necessarily just come in one shape. Engineered joists come in all shapes and sizes. Some of joists have places to set HVAC units, ducts, water supply/returns, and any other material that would need to be run in the ceiling area. Below is an example of HVAC ducts run within the joists. I apologize for the blurriness.

A detail of a K joist looks as such. The top and bottom beam of the joists are called the chord, and the middle area is called the web. - where the triangles take place. This photo is from class lectures.

It is also important to know how the joist is connect to the wall. In this case, the weight of the joist bears on a steel plate that sits on top of the bond beam, which is the top course of CMU that is filled with grout to strengthen it. The photo below shows the attachment of joist to wall.

Mastic Duct Sealant

Above is an HVAC duct. The day I visited the day site the HVAC subs were behind and had to stay late because the ducts were not sealed yet. The mastic duct sealant helps to provide a stoppage against leaking in the ductwork, it is NOT to hold the ductwork together. That needs to be done with hangers, bolts, and screws.

The mastic sealant is a flexible sealant that takes the shape of the material which you are applying it to. According the the Green Building Library, most of the energy loss in a house comes from your HVAC ducts. The loss can equate to 20 to 60% of the air leakage in a home. So ensuring that your home or office properly sealed is very important to reduce your heating and cooling bills. Also, the mastic sealant is being used in commercial work, but is making its way into residential applications as well.

The sealant actually never hardens, so it can withstand the expansion and contraction of materials. The material also acts as a barrier to moisture.

There are other ways to seal ductwork as well. Tape, such as a mesh tape. The tape is similar to drywall tape but is has a different width and is also reinforced with fiberglass. In order to make the best seal on ductwork, use both the tape and mastic sealant. This will ensure a tight seal.

Areas which should be sealed are: around the air-handler, transition or different connections, where a solid connection meets a flexible connection- there is obvious movement from a flexible to a rigid connection, and in building cavities.

For more information on mastic and mesh tape sealants for HVAC usage, visithttp://oikos.com/library/ducts/index.html

More photo's below of different sealant areas.

Control Joints

Control joints are important when dealing with concrete. Throughout the year, concrete will swell and contract depending on temperature. When the weather warms, concrete tends to expand; when the weather cools, concrete tends to contract. Control joints help to keep the concrete from cracking in areas where you don't want cracking.

In order to keep the cracking contained, a joint must be run through the concrete before it dries. Below is a picture of someone "rolling" a control joint in the wet concrete. The second photo is someone using a saw to cut the joint out. Both are acceptable ways of producing the joint.

Marking the line to roll is important. You want to keep the line as straight as possible so that when the concrete dries, it conforms to code. You also want something that looks asthetically pleasing. If your joint was not uniform, it would not serve its purpose for containing the break in the concrete, because as some point or another, concrete will crack.

This photo does a good job at visually explaining the importance of a control joint. If you notice, the crack is not wide, and it follows alongside the control joint. If the joint was not there, the crack could have gone any which way, and caused an eye-sore on the slab. It is important that you do not try to alleviate or stop cracks, but you want to make sure that the crack is controlled.

The last three photos are taken from these websites respectively:

1)https://fp.auburn.edu/heinmic/PerviousConcrete/images/JointCut.jpg

2)http://www.shutterstock.com/pic-19734637/stock-photo-man-cutting-control-groove-in-concrete-slab.html

3)https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdm0axTCrDYyYpknx0oNKSYioCA9GVWeIZGWD-bO7RL5mvqDEg46lZWTI8KkhvyAUFdNVThTyySm0A6ZdU9CxICqU4bIy3PziIa0L8NMb0CZVUhhyphenhyphenoryoTaLWBcLRfFkMdxjJyoMaLtK0/s1600/2010-06-30+09+53+41.jpg

Lintels

This pre-cast lintel, shown in brown, is a structural support member used to distribute load coming from above. In this case, a stained glass window will be put above the lintel in the half-round area. Lintels distribute the load from above around the opening.

Because we are dealing with CMU, arching action is one property that can be found within these units. I would assume there is a purpose of the half round above the window in dealing with the load above. If you roughly draw a line from each end of the lintel, to the top of the half-round window, it roughly makes a 45 degree angle. The half-round would act as the 45 degrees necessary to spread the load out over the lintel. Arching action allows walls to carry and deflect more load than if AA didn't take place. Below is a digram to help further illustrate the role of arching action. The slides are taken from class lectures.

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Buffing CMU

A man above is buffing CMU walls to get the coarse feeling off of the block. This is taken in one of the classrooms. The reason the block is being smoothed out is because it will be painted at a later date. Not only does the block need to be smooth for paint, but also for children who are using the rooms. It would be easy for a child to run along the wall and cut up his or her hands on the block.

Notice the man has all his PP&E on. It is important for whoever is operating the buffer to wear a mask and a face shield. Chips from the CMU could fly up and potentially damage your eyesight. Also, small dust particles fill the surrounding area, and it is important that you don't breathe the toxic particles in.

Temporary Bracing

The orange steel tube is connected at both the slab and the masonry wall. This temporary bracing provides support for the wall until completion as well as ensuring the the wall remains plumb. When the wall is at a hight okay for the bracing to be put up, typically specified on the specs, bracing will be inserted into the mortar and also on the slab. The bracing on the mortar fits around a block, as noted in the picture below.

From there, the rod is attached to the wall bracing with a bolt and pin. The bracing has different holes where the bolt can go in depending on the height of the wall. This gives flexibility if you have to bolt the rod on the slab closer or further away from the wall because of conduit or other material coming out from the slab. Next the rod is attached to the slab in a similar fashion to the wall.

Although this picture doesn't show it, normally the rod allows you adjust its length so that you can get the wall plum. This allows one to fine-tune the rods length so that the wall is as close to plum as possible. It is so important that the adjustments are made because you are dealing with small units of measurement to correct a walls level. Again, the rod is attached to the ground with a bolt and pin. The bracing is held firm in place by a bolt that was shot into the concrete and then screwed tight to ensure it won't move.

Ladder Mesh Reinforcement

When laying brick and block, you need to have lateral reinforcement within your courses above and beyond your vertical reinforcement such as rebar. The above photo is an example of what a ladder reinforcement looks like to tie both block and brick together. The main ladder, the widest part shown on the right, is used for the block course. Typically, these are set every three courses and keeps the block from moving laterally and provides extra reinforcement when the block moves due to weather or other conditions.

The left "ladder" is used to tie together the brick course with the block. Here is a photo of block that has already been laid, and waiting for the exterior brick. It shows how the only thing extruding is the brick ties.

The brick is not laid directly next to the block. Usually, there is an air gap in-between the block and the brick for air to travel up and down in order to help dry up any moisture that is trapped between the brick and block. The picture below helps to illustrate this point further-

Also, flashing put in between the air cavity between the block and any sort of exterior facade to further help mitigate any moisture from traveling up the cavity, known as capillary action.

Below is a photo of some interior or exterior ladder mesh reinforcement for only block. One can tell this because it is only the one ladder system with no extrusions coming from the ladder.

The second to last photo was taken from - http://www.designerpages.com/products/119345-270-Ladder-Eye-Wire

Rollers

Rollers, or sometimes called compactors, are used for compacting soil, gravel, asphalt, etc... for constructing roadways or large foundation areas where concrete will be poured. The main use for these rollers are to smooth out roadways prior to laying asphalt. It is similar to a fine grade for finishing a grade around a building.

How does a roller work? It uses its weight and vibrating action from inside the roller to compact and flatten the area it covers. One thing I didn't realize is that in some rollers, you can fill the inside of the drum(front smooth roller) with water to achieve the particular weight that the roller needs for the job. For different applications, a roller needs to have certain weight standards in order to smooth different surfaces. If the roller is too light, then the end result will not be met and the area being rolled will not be compacted enough. Thus, your final product will be unsatisfactory.

Below is a video that I took from the Prices Fork Elementary school compacting a mid-size stone temporary road for equipment to get in and out. Since winter is already here, stone roads are needed for equipment to drive on. If these temporary roads aren't in place, equipment may sink into the wet soil and create a mess around the job site - a nightmare for any contractor.

The top image was taken from - http://www.davidtate.com/compaction.htm