Friday, August 22, 2008

Structural Modifications

The sliding doors are very sensitive and can rack easily. After a month of wrestling with them, I installed simple aluminum cross braises on each door. I drilled a hole through each horizontal brace in the door and used a piercing screw to hold the diagonal brace to each section. This made a HUGE difference and both doors now glide open.

I really wish that Harbor Freight just made a regular door instead of the sliders...I'm sure it's all about saving a couple of bucks.

The most important addition I made was adding some extra bracing. During windy days, I could see the end wall bowing in and out...especially the entrance wall since the cross bracing is really poor. I bought some standard 10' x 1/2" conduit. I cut them in half and pounded down each end to make them flat and drilled a hole in them. I bent the flat piece at about a 45 degree angle for the wall side and then sort of held it in place to figure out the angle of the rafter side. I was able to use 2 pieces total for the 4 "corners"

I was also very concerned about the snow load during the winter. If there is a heavy weight on the roof, the walls will bow out quite a bit. (I tested this by hanging off the top rafter support beam!) I built a tie-rod by taking another piece of conduit and cut it to around 7'. (I measured the distance between the bolts of the angle braces to determine the distance of the holes in the tie rod.) I pounded down the ends and bent them to about 30 degrees. I also pounded down a spot in the center of the rod and drilled a hole in it. Just by luck, the remaining piece of conduit was just long enough to attach the peak of the roof to the tie rod. This simple structural change added a lot of additional stability and made the roof extremely rigid. The tie rods are tall enough where I can easily walk under them, and also hang a bunch of plants from them. The trick is to get the angles of the rods correct!

Another note. Some conduit can be brittle. I heated the ends with a MAPP gas torch so it was about red hot and pounded it down with a lump hammer on my vice. Also the coating on the conduit can be toxic, so do it outside.

<<Glazing | Additions>>

1 comment:

Denton said...

A better option for bracing would be to have the cross braces tie into the top of the wall plate where the rafters attach. I used the extra slider screws with L braces to attach to the wall stud and then inside the 3/4" emt rod. I have 5 braces total for each rafter running the width of the This makes a huge rafter tie structure. Keeps the walls from bowing out with roof weight. Your attachment location actually causes the rafter to pull down. Just a thought. With the ridge support pushing down you want the load to transfer to a vertical wall not an angled rafter.