Posts Tagged ‘Construction’

Home Construction Shop Steps to Hand Cut a Gable Roof

Tuesday, July 7th, 2009

Hello everyone , welcome to Home construction shop and steps to Hand cut a basic Gable end roof. For the layman a gable end roof is depicted below. Note the ends are straight up and down as opposed to a cottage style roof or a Hip roof as it is referred to sometimes, where all side of the roof are sloping.. The Gable end roof is fairly easy to build but is still a fair amount of work.

08-roof

In his section of  Steps To Hand Cut a Gable Roof  the Home Construction Shop will cover the the procedure to measure and layout the rafters in your home construction project.

One of the most important tools to cut a roof is a framing square, here are some basic components of a framing square below. The shorter thinner measure of the square is known as the Tongue. This is the side that the lesser measurement of the pitch will be gauged when layng out the rafter. In a 7/12 pitch roof you would use the 7 inch mark  on the tongue measure. The longer , thicker measure of the square is known as the Blade. The larger of the measurements is gauged on this side. In a 7/12 pitch roof you would use the 12 inch mark on the blade measure. Always remember to gauge your measurements using the values on the outside of the square.

fig-20-framing-square

The first step in your home construction project of framing your roof , is to calculate the span of your rafters. The length of rafter is determined by two factors.

1. Roof  Pitch – This is ratio of horizontal length to vertical length. For example if the roof pitch is a 7/12 pitch. Which will be indicated in the drawing. For every 12″ of horizontal length or ” run” there is 7″ of vertical height or “rise”. The diagram below depicts this

roofpitch3

2. Structure width- This is the width of the building as determined usually by the shortest span , or as indicated in the building drawings. This measurement would be taken from outside of the framing on one side of the structure to the out side of the framing on the other side. The diagram the Home Construction Shop shows below depicts this measurement.

span

By dividing the span of the structure in half  we will be able to calculate the run of the rafters. As the Home Construction Shop depicted above , a span of 24 ft. divided in half will give the run of the rafter which is 12ft. Knowing , both the pitch and the run of the rafters it is easy to calculate the height that the roof will be from the top of the Wall to the very peak of the roof.

Since the pitch is 7/12, then for every 12″ or 1ft of run , the roof will rise 7″, so…. if the run of the rafters is half the span of the structure , 12ft as depicted above, then the roof will rise 7″ x 12 ft = 84″ or 7ft. I know this is not easy math for some but at the Home Construction Shop we feel its good to go through to get the easier picture and a full understanding.

Lets say that the span of the structure was 32ft. Then the run of the rafters would be 16ft. With a 7/12 pitch the rise of 7″ for every foot, then we would calculate 7″x16ft.=112″ or 9ft. 4″

I hope you are still with me so far.

Now that we have our run for the rafter lets go through the steps to layout the proper length of  the rafter. There are a couple methods of laying out the rafter. The quickest way at the Home Construction Shop would be to use trigonometry and the Pythagorean Theorem. This methods is calculated using the equation ( a2 + b2=c2).  Below is a video with a bit of a math lesson showing  how to calculate the Pythagorean Theorem, assume that the letter X in the video is the rafter, lets have a look and then plug our own numbers in.

So , if we plugged in our numbers we could find the length of the rafter, lets see;

(A) squared will represent the height of the roof from the top plate to the peak and we figured out that with the 7/12 pitch and half the span of the building at 12ft. A rise of 7″ for every 12″ or 1ft. would equal 84″ or 7 ft.

(B) squared will represent the half span of the building which is 12ft.
(C)  squared represents the rafter. So..

(A) squared = 7′
(B
)  squared=12′
(C)
squared=?
7 squared =49
12 squared=144
49+144=(C)
squared
193=(C)
squared
the square root of 193=c
c=13.9ft. or 13′ -10 7/8″

Once this measurement is achieved all you would have to do is mark your ridge cut and then measure down the rafter stock , 2×6 or 2×8 whatever you are using for your Home Construction roof framing project and mark the outside edge of the building or structure line , this is where the birds mouth will be cut out. See the first diagram below.

NOTE: In the second diagram below, the measures on the square are doubled  12″  on the tongue as shown and 24 ” on the blade. Here the diagram shows an 12/24  pitch setting on the square.  This is the same as a 6/12 pitch. Doing this gives you the full use of straight edges across your rafter to scribe or mark

measure-r-l

The final mark on the edge of the square represents the outside of the structure and the plumb cut of the birds mouth. To mark out the birds mouth take note on the diagram below the the Home Construction Shop has provided.

birdsmouth

Once you have the outside structure edge marked , take your square and flip it the opposite way with your measures still on the outside of the square but set on the top side of the rafter as the Home Construction shop has shown in the top diagram. Now slide the square so that the width measurement of the exterior wall top plate sits at the outside structure mark. In this top diagram it is showing using 4″  measured on the inside of the square. This measurement  represents the wall thickness where the birds mouth will sit on a 2×4 top plate, 31/2″ for the plate , and a 1/2 ” wall sheathing. Once this is marked remove the section shown.

Next step in your Home Construction roof framing project is to layout the overhang. View the diagram below

tail

Once again with the square flipped and the gauged measures on the top side of the rafter, align the outside edge of the tongue with the back of the birds mouth as shown in the top diagram. Mark off 10 1/2 ” to represent the overhang. Now flip the square back over and align your tongue at the 10 1/2″ mark that you made with the pitch settings aligned with the bottom of the rafter as the Home construction Shop has shown in the bottom image.

The final cut is the fascia cut. The length of the fascia cut is determined by the width of the fascia. If you are using 2×6 for fascia the length of the fascia cut should be enough to account for soffit and fascia board.  So,  5 1/2″  for the 2×6, subtract 1/2″ – 3/4″ for soffit and fascia flashing = 4 3/4″ – 5″

tail-2

Here is a sectional view of the components of a hand cut roof below.

anatomy-of-a-common-rafter

Well… I hope you have gotten a layman’s understanding of everything here. If you have difficulty , feel free to comment and leave an email and Home Construction Shop will be gladly to help more. Continue browsing the Home Construction Shop to learn how to measure your rafters using the square and the step down method. A little bit more time consuming but not difficult. S o c’mon in to the Home Construction Shop.

Reblog this post [with Zemanta]


Home Construction Shop Safety

Monday, July 6th, 2009

New Circular Saw Safety Technology

Safety First for Home Improvement

Home Improvement has become popular these days. Whether doing it to make a living, to save money, or for pure enjoyment, many people are drawn to the do-it-yourself trend. While this can be a very lucrative way to do construction, just like with professionals who build for a living, safety is a key to any project. Without using proper safety devices and procedures, disaster can happen on the simplest of home improvement jobs. Accidents are possible when working at heights, with heavy, noxious, or awkward materials, with power tools including those with sharp blades, or with electricity or gas. While accidents are possible at anytime doing anything, the preceding situations are when you need to be especially careful about doing construction. The most common safety procedures include those to do with your comfort with the job, your work area and equipment, and some just plain common sense.

One way to stay safe on the job has to do with your comfort with the job. Many do-it-yourselfers are old hands at doing home construction. Some are just starting out. Whatever category you fall under, safety is of the utmost importance. Only tackle jobs you feel comfortable with doing. If you feel that your home construction project is too advanced for your skill level or that you don’t exactly know how to handle a power tool, be smart. Do your own electrical work only if you know for sure that you have the expertise to do so. Don’t let being prideful get in the way of being safe. There is no shame to admitting you do not know how to do something. It’s not just the newbies that get hurt, either. Many experienced do-it-yourselfers become cavalier about their abilities and cut corners when it comes to safety. No matter how good you are and how much you know, always keep safety in mind as accidents DO happen to the experienced as well.

Another way to stay safe is to mind your work area and equipment. Besides making work much more efficient and quick, keeping an orderly work area is also a key to avoid creating dangerous hazards for yourself. Many things can go wrong in a home construction project as it is without us creating problems for ourselves. Do not allow electrical cords to tangle as they could become a tripping hazard. Store all tools properly, especially focusing on power tools, sharp tools, and things that can cause injury. When working with lumber, be sure to pull all the nails that might be in it. Another thing about your work area is to keep children away from it. Also, keep tools out of children’s reach.

As for equipment, this includes what you wear. Dress as safely as possible. Don’t work in sandals and shorts. Hearty clothing, like jeans, work shirts, and gloves help to protect you while you work on your home construction project. When using hammers, and power tools that may toss shavings or wood chips, wear safety glasses or goggles. These help to protect your eyes from flying debris that can harm them. Also, keep drill bits, cutting tools, and blades sharp. If they become dull, tools can seize, making it extremely dangerous.

Keeping these safety tips in mind, most of the time, accidents can be avoided just by using a little common sense. Don’t go up to the roof to work during a thunderstorm. Don’t run electrical cords through water while you are using live tools. These are things that you don’t have to be a contractor to know aren’t smart.

Finally, keep a trusty first aid kit around for emergencies. These are available in many stores. All of these tips can help you avoid accidents on the way to your do-it-yourself masterpieces and all home construction projects.. Remember, only do jobs that you are sure you can tackle on your own, keep your environment free of clutter, tools stored properly, and use your common sense about safety. Keep in mind that one example of the injuries that occur when doing home improvement is falling from ladders. According to studies, more than 2 million people were treated in U.S. emergency rooms for such ladder-related injuries from 1990-2005. Always remember that safety is the first and most important rule to remember when attacking a do-it-yourself project.

Below is one of the most amazing safety technologies that i have ever seen .  The most advanced table saw safety device that has ever been designed. Watch this Video with the same amazement and  intensity as I have.



Reblog this post [with Zemanta]


Bad Behavior has blocked 37 access attempts in the last 7 days.