Construction question

[Mick]

I know this is way off topic, but I'm hoping a couple of construction types can answer a question. I'm building a frame to store my Vbox outside and I'm ready to make a couple of braces to rest the box on. If I nail three 2x6s together would I have the same strength as one 6x6? If it makes any difference, I use an airgun with 3.5" 16d Bostitch nails.

My other idea, if I mill out anything would be a couple of spruce 8x8s.

[Waterchikn]

If I knew what kinda of span and weight you were dealing with, it would be alittle easier to answer that question. I am not sure how you have it designed in your head, but if you give us alittle more info, we can definitely point you in the right direction. And also, the 3 2x6 are going to hold more weight on a longer span, assuming they are upright and not laying flat and considering they are the correct species. 6x6's are usually for "verticle" support. I hope this helps.

[cat320]

It's always better to use multiple pieces but i would not nail them but bolt them together but for the cost I would just up the size to a 2x8 if it was mine you can never have enought suport.Or you can put a fletch plate in it and use less wood.

[Mick]

The Vbox weighs 750# and the span is 7'6". These are spruce pine boards (these particular ones are salvaged from a boatyard and are commercial dimension 2x6s). I don't know what the technical term would be, but my idea is to have the 6" side vertical, then nail them so that horizontally you'd have 2"/2"/2".

Starting on the ground, I put 8x8x16 concrete blocks and leveled them using a laser level for a base. I then poured sand around each block to keep them steady. Then I put 8x15 1/5 blocks of pressure treated on the top of each block. Then I put a 2x6 from one block to the other on each side of the frame, making sure they were level - end to end and side to side. The whole thing will now be level. Then I built four frames - one to go on each block - each 15" wide and 34" tall. The four sides are made of 2x6s. In the middle of each frame are two vertical 15" 2x4s - the edge of one forms a "T" to the other. I'm hoping that by building them that way, the weak point here is the concrete blocks.

Now I'm ready for those boards that the Vbox will lay on and that's where my question comes in. You can tell I'm not a carpenter, but I like to do things right. If you have any suggestions of what I could do better, please let me know.

[Mick]

Cat - thanks. I think I'll do that. I've got some 2x8s laying around. Question - what's a "fletch plate"?

[Mick]

Sometimes it just takes someone else to steer you in the right direction. I was thinking in the wrong direction:headwall :headwall . Thanks, Cat. I was upstairs of my garage looking for a 2x8. Could only find one 10' piece. Then I thought - What about a 2x12? I've got two 17' pieces. Use one, cut it in half, plenty long enough and a whole lot stronger. Should hold 750#.

[cat320]

Mick it's a flat piece of steel you sandwich in between the wood and lets you nail on the outside of it but make it not sag when you put weight on it. If this is to be a do it once and do it right thing i would go all out but if it is to be a temporary thing then I would not.

[Lawn Lad]

Fletch plates were more common as garage door headers before LVL beams became more standard. Fletch plates require lots of drilling/bolting to hold the whole package together.

[Pelican]

Mick, the 3 2x6s bolted together with carriage bolts should be stronger than a single 6x6. What you end up with is a laminated beam. That will be more than strong enough to support 750 lbs over 7'6". The 2x12s will work fine as well.

[BWinkel]

Mick
Three 2 x 6 nailed together can carry 1200# concentrated load for an 8' span. This assumes 2 x 6's are SPF #2 or better, are free from defects and are properly nailed together.
Bill

[digger242j]

Just for the sake of clarity, it's "flitch" plate, not fletch. I used to think they were called flinch plates, until an architect corrected me. (Or maybe it's a regional difference in what they're called.) I did get lots of results when I searched for "flitch plates" on Google.

[Lawn Lad]

Ah yes... flitch plates. Fletch was one of Chevy Chases last good movies that he made when he was actually funny.

[cat320]

Thanks for the correction .You would of thought that some one close to me would of set me straight on the correct name .:D

[digger242j]

You would of thought that some one close to me would of set me straight...

Hey, Cat, look at the bright side--you could be Chevy Chase and not have anyone close enough to tell you that your movies aren't funny anymore... :)

[cat320]

So mick did you build it yet?I was just thinking of one my farthers friend has for his sander but it's a four post system so he can lift in the front and back if i remember right.I should see if i can get some pics of it some day.

[Mick]

Got it built. I had been wanting to get some pictures to post, but the wife had the camera in Iowa the past two weeks. She just got back at 10:30 last night. I finally wound up using 2x6s instead of the 2x12s because I have plenty of 2x6s and want to save those 17' 2x12s for the building I'm putting up this summer. Also, as I read through all the great advise, I realized that I intended this to be very temporary (just for this next summer) and that there would be two sets of 2x6s holding the weight of the Vbox. I'll be using the chain fall set up I have in the garage to get it set on here. I haven't moved the Vbox yet - waiting for it to dry up, then I'll move it out of my garage and cover it with a tarp. Notice that I put a 1" piece under the end of each span for lateral stability.

[cat320]

Looks good mick just looks kinda low for the truck and sander must just be the way the pic was taken. I see i a nice area for a modern garage and under floor heating and inside storage .:D Looks like you have ample room up there to build your dream garage.

[Pelican]

Mick, you need to put some diagonal braces from your upright supports to the horizontal 2x6s. If someone leans on your structure with enough weight, it will fall over.omg

Four foot lengths of either 2x4 or 2x6 screwed at 45° to the uprights should be plenty to stiffen it up.

[Mick]

Thanks. Yes, there's plenty of room. This is a five acre site. Pelican, good catch. There are 8" blocks of pressure treated 2x8s in each hole of each concrete block. My idea is to nail 2x6s to the inside and outside of each block, halfway up the uprights. I had thought of your idea, but there's not room. The horizontal bars need to come off to back the truck with the sander on. Then there's only about six inches clearance from the horizontals to the flatbed. The sides of the flatbed clear the side supports by only an two inches on each side.

I designed it with close clearances on purpose. I wanted to keep it as narrow as practical for strength of the supports. Then I wanted to keep in as low as possible to minimize the distance I'd need to hoist it with the manual chainfall.

What I might do, is design something like Pelican said that can be screwed in place once the sander is placed on it and the truck is driven away. Is that what you mean?

I'm just kind of thinking as I'm typing.

[Pelican]

I'm missing something here. Mick, how will you get the sander from the truck to the stand? If I understand correctly, this is to store the box on top of, not to use for hoisting the box, correct?

What needs to go under the stand that would interfere with the extra bracing? If you are careful to not side load the stand while placing the box, it should be OK, but I'd put that bracing in for long term storage. I definately wouldn't work under it without!

[Mick]

I'll be using the framework that I have the hoist on in my garage right now. I'd use that to lift the box off the truck, slide the 2x6s into place and lower the box. For loading, the flatbed then needs to fit under the horizontal 2x6s.

Here's a picture of the hoist that I'll be using:

[Pelican]

OK, I understand what you're doing.

You'll have to have some sort of bracing to prevent the support from toppling due to side loading. This is even more important since the top rails are portable. Diagonal cross bracing from your front to rear supports is probably a good idea too.

For the side supports, I think I'd use pressure treated 2x6 screwed to the sides of your support columns extending down to ground level. From there attach another 2x6 the same length as the last one, laying on the ground perpendicular to the column. Use a third piece of 2x6 to form the hypotenuse or diagonal. You'll need one of these on each support column.

[Mick]

Ok, thanks a lot to everyone.

[Pelican]

Mick,

Here's what I cobbed up to support my Torwell V-box. The Torwell weighed about 1000 lbs. I had a crank up hoist rigged up, I'd raise the v-box up, drive out from under it, and slide the horses under the box.

These are made of pressure treated 2x6 and 2x4 and have seen 5 seasons use.

[Pelican]

These worked very well and are solid as a rock. I was very comfortable working on top of or under the V-box