DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   Ideas on reinforcing attic joists (http://www.diychatroom.com/f19/ideas-reinforcing-attic-joists-125271/)

PhaTea 12-01-2011 08:14 PM

Ideas on reinforcing attic joists
 
Hello,

I recently purchased a 1950's ranch home which has an attic ladder installed for attic storage by some previous owner. The problem is the ceiling under the area decked in the attic is cracking now that my wife and I are storing things up there. Nothing super heavy, just clothes, knick knacks, and assorted holiday decorations. I can also tell, now that I have taken a better look at it, that the ceiling has definetily been repaired for this problem before.

I really don't want to have to give up workshop space in the basement for the things we intended would be stored in the attic. So am looking for some advice as to how to strengthen the joists to better handle the vibration and deflection.

Attic Details
-Gabled roof with 2*4 rafters spaced 24" on center.
-Ridge collars
- No Purlin, but 2*4 struts are cut to fit between rafter and joist (There is a strut on every rafter).
- 1*6 hanger running from every rafter to its corresponding joist.
-The joists themselves are 2*4 spaced again at 24" oc
-joist span 14' ext. wall to middle load bearing wall and then 12' from middle load bearing wall to other ext. wall
-5/8 osb screwed down to joist for decking

The decked area runs down the middle of the attic about 8' wide the entire length of the house about 45'.

Can I install some strong backs? I will sacrifice the lose of head room for keeping the storage. If I installed four spaced evenly under the decked area would this help? would I be adding too much weight with the new amount of lumber? Ceiling is plaster on gypsum board backer and weighs a ton.

Can I sister in some 2*4*8s or even 2*4*6s to the joists under the decked area in order to help stiffen and deflect the weight above or would that just be a waste of time since they wouldn't be connecting to the load bearing walls? Like I mentioned this is only for storage and nothing overly heavy.

In order to add new joists to cut down distance I would have to use 14.5' boards and there is no way of moving them around in attic for positioning.

Sorry for the long post, but I am not a roofer or framer, just a DIY'r (more out of necessity than choice). It is not my ability that I question, but my knowledge of the task at hand. I thank you in advance for any suggestions, guidance, and/or direction you may be able to provide.

Travis Rian.

joecaption 12-01-2011 08:34 PM

That attic as you found out was never intended for any type of storage.
Unless you can get long enough 2 X 10"s to span from the top of the outside wall to the center wall your wasting time and money.

Ron6519 12-02-2011 09:19 AM

There's no way to store anything on a 2x4 joist structure. If you want it for storage, you need to look at the unsupported spans under this floor and install a floor joist system that addresses the spans.
You can reinforce part of the floor as long as you restrict the storage to that space.

gregzoll 12-02-2011 10:57 AM

It either cracked before, after the home was built, or the previous homeowners placed very heavy objects up there, and over time the members cracked. You really need to have someone come in and inspect the joists to see what needs to be done. Worst case, it may just be typical cracking, from them drying over time. Without pictures, it is hard to tell you.

If you want to see a severely cracked ceiling framing member, I can post a picture of one in my garage that you can compare to.

Wildie 12-02-2011 02:41 PM

Quote:

Originally Posted by gregzoll (Post 783932)
It either cracked before, after the home was built, or the previous homeowners placed very heavy objects up there, and over time the members cracked. You really need to have someone come in and inspect the joists to see what needs to be done. Worst case, it may just be typical cracking, from them drying over time. Without pictures, it is hard to tell you.

If you want to see a severely cracked ceiling framing member, I can post a picture of one in my garage that you can compare to.

Greg, I read the OP to say that the plaster cracked, rather than the members.
Perhaps the OP can clarify this!

gregzoll 12-02-2011 02:47 PM

That can happen over time. I have Rocklathe in my house, and it has cracked in various places along seams. After the earthquake we had in our area, cracks became more noticeable in various areas, that were not there before. Even after we pulled a wall, that was not load bearing, cracks appeared.

If the home was closed up for sometime, and then the heat was turned on, the expansion and contraction of the home can cause cracking. Does not mean that there was a heavy load up in the attic, means that the home was just flexing its bones, which all homes do.

titanoman 12-02-2011 06:28 PM

Can you run some 2 x 4 legs (kings in a truss) from the rafters straight down to some blocks screwed to the joists (through the plywood), essentially hanging the joists, then run"kickers" (purlings) from that point on the rafters to the interior wall? (building a half-truss, more or less).

Gary in WA 12-02-2011 10:16 PM

Welcome to the forums, Travis!

Please post same exact question in only this one forum, thank you, Gary

AndyGump 12-02-2011 10:40 PM

Quote:

Originally Posted by titanoman (Post 784296)
Can you run some 2 x 4 legs (kings in a truss) from the rafters straight down to some blocks screwed to the joists (through the plywood), essentially hanging the joists, then run"kickers" (purlings) from that point on the rafters to the interior wall? (building a half-truss, more or less).


Are you serious?

Andy.

titanoman 12-02-2011 10:43 PM

Quote:

Originally Posted by AndyGump (Post 784475)
Are you serious?

Andy.

You don't think this is a good idea? Why not?

AndyGump 12-02-2011 11:04 PM

Sorry if I seemed a bit harsh there Titanoman.

We don't know anything about his location or what loads are for the roof, hanging the CJs from the RRs is just transferring loads that were not meant for the attic area to what sounds like undersized RRs.

The OP needs a full design on this situation or take out all the crap in the attic that is not meant to be there.

Andy.

titanoman 12-02-2011 11:11 PM

Quote:

Originally Posted by AndyGump (Post 784496)
Sorry if I seemed a bit harsh there Titanoman.

We don't know anything about his location or what loads are for the roof, hanging the CJs from the RRs is just transferring loads that were not meant for the attic area to what sounds like undersized RRs.

The OP needs a full design on this situation or take out all the crap in the attic that is not meant to be there.

Andy.

No. The weight of the joists is transfered to the interior wall via the "kickers". Functions like the webbing in a truss. It would work fine- no load on the rafters.

forresth 12-02-2011 11:15 PM

sounds like about all you can do is store stuff right over interior walls, turning them into minor load bearing walls.

a better option would be to just not put anything up there and pull the plywood out.

titanoman 12-02-2011 11:24 PM

Quote:

Originally Posted by forresth (Post 784510)
sounds like about all you can do is store stuff right over interior walls, turning them into minor load bearing walls.

a better option would be to just not put anything up there and pull the plywood out.

You're not seeing it. The center of the floor is hung from the rafter; from that point of the rafter, run an angled brace(it will look like the opposing rafter) back down to the interior wall. The weight of the center of the floor is transferred to that wall and the exterior wall. We're making trusses, basically.

Gary in WA 12-03-2011 06:53 PM

A stressed truss would be designed for storage when they meet the minimum strut (open-space) placement; they don’t necessarily come that way. They are designed for roof/ceiling loads only. To suggest building one (or part of) with existing rafter/ceiling joists without engineering would not be recommended by me. The lumber grade/species, gussets, connections, and fasteners need to be approved by a local AHJ. Let alone the camber required to lift the ceiling off the walls below – now acting as load-bearing with storage materials that shouldn’t be there.

Many homeowners load storage material on existing over-spanned ceiling joists that do not meet today’s minimum safety codes. The problems seen have prompted the 2009 IRC to now include minimum load ratings for attic storage joists; http://docs.google.com/viewer?a=v&q=...1txlzU01V4JQIg

http://publicecodes.citation.com/ico...002_par017.htm

With a partial truss, the now-bearing wall needs a double joist under it or sufficient bearing to the earth to transmit loads to below.
Safety is my #1 concern……

Gary


All times are GMT -5. The time now is 03:07 PM.