As I do my homework in preparation for my much-awaited 2nd floor addition, I ask you guys to give me advice on tarp protection. I will be removing the roof, installing new plates over the 2 x 6 ceiling joists, framing a new floor deck, putting up the new walls and roof on my 22 x 40 home. All this while leaving the 1st floor ceiling intact (aside from the stairs and HVAC openings). I will need tarp protection at every stage of the project, i.e., after removing the roof, after installing the deck, and after framing the new roof.
Do they make any recommended, construction-grade, heavy duty tarps? What’s the largest sized tarp available? What is the proper technique in installing tarps? Two neighbors, with the similar 2nd floor addtions, went through ordeals when the rainstorms struck. Both had tarps, both suffered tarp failure, and both had 1st floor water damage.
I understand that there may be no foolproof way, but how can I increase my chances – in preventing possible rain damage – during the framing of my new addition. I give myself two days for demolition and prep work; 2 days for the floor deck; two for the walls; and two for the roof.
Edited 5/6/2009 5:58 pm ET by djthx
Replies
The polyethylene tarps I use come in sizes up to at least 20X30 (nominal) . They come in various thicknesses which are reflected in the price. The cheapest seems to last me about 10 months depending on the solar exposure (UV resistant tarps are also available). I like to fasten them down by screwing through the grommets and hems (edges) with screws and fender washers. Other fastening systems are available.
It is also important to keep the wind from moving the tarp excessively which may necessitate weighing down the inner portion or if that is impractical I will secure it with cleats using minimum amount of screws. Screws, of course, make it easy to remove and reinstall the tarp throughout the process.
The steeper the slope the better the tarp will shed water. Ideally you would install the new roof before removing the old one but this if often impractical.
Edited 5/6/2009 2:47 pm ET by sisyphus
Edited 5/6/2009 2:56 pm ET by sisyphus
Thanks to all for all of your suggestions. I will post responses and follow up questions later on.
I've been through this more than once; there is no foolproof way to keep all rain out of a house once you tear off the roof, so be prepared to deal with that fact. Move anything that absolutely must not be water damaged to the basement, place it all on skids, and cover it all with poly sheeting that is 'tented' so it won't accumulate puddled water.
Most construction tarps are woven polypropylene; you can get them in sizes up to 30x40 feet. The most important thing you need to remember when tarping is that tarps, like shingled roofs, are not waterproof--they will only shed water. They will not resist pooled water for more than a few minutes.
You need to erect a temporary ridge over the house while the roof is off, and drape your tarp(s) over that. The edges of the tarp must extend down beyond the top of the house walls, and ideally they would be guy-roped away from the walls, too, so drip-off water won't run down the face of the house.
Tarping is a major PITA; at the end of a long day on the site, the last thing you want to do when cleaning up is start building what amounts to a quickie roof frame and then dragging heavy tarps over it while standing on a step-ladder or some such. You need to be at least three or four people. There just isn't any easy way to do it.
You can use 6-mil polyethylene sheeting instead of those big blue tarps, but it only comes 10 feet wide so you'll have to tape sections together with Glasclad (red) tape. Poly sheeting is lighter and usually less expensive than tarps, and it is waterproof...but it tears and stretches, it isn't very tough, and it will get pierced by nails and splinters while you're dragging it on and off the house. You'll wind up patching it every day and replacing it often anyway.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Good point about pulling the edges out and away from walls so drip-off water won't run down the face of the house. When I helped a friend build an addition, we tarped the roof just before a weekend of rain and he stretched the edges of the tarp down and pulled them over the roof edge and inward and attached them tight with cleats to the wall (against my advice--but I didn't know what to do other than let them hang free, which might have been a problem too--especially if the wind caught them). It rained Friday night and he was out in the middle of the night pulling the cleats off because the water was running in a torrent down the tarp and down the walls and right into the joint between the old house and the new addition. Really messed up the plaster inside at that corner.
"You can use 6-mil polyethylene sheeting instead of those big blue tarps, but it only comes 10 feet wide so you'll have to tape sections together with Glasclad (red) tape."http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100651802just in case there's ever a need...http://www.tvwsolar.com
Now I wish I could give Brother Bill his great thrill
I would set him in chains at the top of the hill
Then send out for some pillars and Cecil B. DeMille
He could die happily ever after"
20-foot wide poly. Good to know. Thanks, bro.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Thnx for your comments. I plan to do most of the demo on the 1st day, including the removal of most of the raftters. I plan to leave both gable ends up, along with a few rafters to support the ridge (to facilitate a tarp overnight). The roof is about 40 ft long. How many rafters do you think will be able to safely hold up the ridge for this purpose?
While the roof is off, can I make the temporary "tarp ridge" out of 2 x 4 material? Are temporary rafters necessary? If so, about how many? What slope will suffice?
Once I have the walls up (before the rafters), I guess I should also erect a ridge that's higher than the walls and use the same system, right?
Can I trust the tarp holes to securely hold down the tarp, or should I use furring strips rolled over at the ends?
Edwin
The roof is about 40 ft long. How many rafters do you think will be able to safely hold up the ridge for this purpose?
If it's just a 2x ridge board, 10 (5 each side) oughta do it. That'll divide your ridge into 10-foot spans. Just watch out for the joint(s) in the ridge and sister them if necessary.
If it's a ridge beam, you should leave the mid-span post(s) in place, but you can take out all but one rafter set every ~14 feet.
In both cases, it would be an excellent idea to install temporary knee braces between the gable wall and the ridge (if there aren't already some in place) to prevent the whole thing from racking over sideways.
While the roof is off, can I make the temporary "tarp ridge" out of 2 x 4 material? Yes.
Are temporary rafters necessary? Use 1x3.
If so, about how many? 5 pair.
What slope will suffice? 6 in 12 is good if you can do it. 4 in 12 minimum.
Once I have the walls up (before the rafters), I guess I should also erect a ridge that's higher than the walls and use the same system, right?
Yes. Run the 1x3 'rafters' right past the top plates of the walls so you create some 'eaves' when you drape your tarp.
Can I trust the tarp holes to securely hold down the tarp, or should I use furring strips rolled over at the ends?
1x3 rolled/nailed into the tarp edge will be the most secure, but ideally you don't want to nail those directly to the walls. One idea is to run guy ropes from those weighted edges to pegs or some other solid point (scaffolding, tree, whatever) and haul the tarp taut with the ropes so the edges flare away from the building enough to keep run-off water off the walls.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I've bought sheet poly in up to 40' width.
Would that be the 6-mil weight for VB, or the 2-mil disposable stuff for DIY dropcloths?
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
What I got was from a supplier "Guardian", in Pueblo, CO.IIRC, it was 6 mil. black. I bought it to put under a building where we wanted no seams. 40' x 100' roll.Some believe it to be effective mitigation for areas where substantial radon comes out of the ground. It's also used to stabilize underground moisture under buildings and roads where expansive soils are a problem. I first heard about the application from a buddy who's a Fed highway engineer.I want to say it might even have been 8 mil. That was 6 six years ago.The main thing I remember is that is was the HEAVIEST roll of plastic I ever worked with! <G>
What I got was from a supplier "Guardian", in Pueblo, CO.
IIRC, it was 6 mil. black. I bought it to put under a building where we wanted no seams. 40' x 100' roll... it might even have been 8 mil.
That's excellent info; it goes in the database....
Thanks.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
A typical point of failure for any tarp is how it's set up to (not) drain. Things look good until it gets wet and weighted down. Then it develops swimming pools. You need to plan pretty carefully to ensure that water will shed from all areas of the tarp. This sometimes means almost building a temporary roof structure under the tarp. Avoid members across the low end of the tarp -- try to have all the tarp supports going parallel to the slope - like rafters, but with no plates to catch the water.
If you're not sure, test it with a hose and make sure the drainage is working for ya. Liberal use of cap nailsd, firring or other wind-resistant hold-down methods are pretty much required.
Oh, and make sure you're insurance is paid up! ;-)
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
Thnx Mike for your response. How many temporary rafters do you think will suffice for a "tarp" ridge? What slope do you recommend? Will 2 x 4s do?
Edwin
i'ld agree with all dinosaur said. specially pita at the end of a long day . without some sort of ridge you can end up with so much water on a tarp you cant remove it . on a 30x 40 log house i saw it take two days to get atarp drained enough to be removed and it was leaking like a sieve all that time as well. you can buy tarps for covering hay at farm supply stores that are much more leekproof. they alot more than the cheap blue ones. they also come in much larger sizes. i'm not sure but i think you can order them to custom sizes. someone gave me a phone # 1 800 hay tarp. i havent tried the number but maybe that will help. good luck it's always a little scary having a roof off.
I used to work for a company that did insurance work, leaky and burned off roofs needing a temporary (up to a year) coverups. I put down 6 or 8 mil poly, after making sure drainage is right, then I put blue (cheap) tarp over it and secure with cleats. I plan ahead for removal and coverup to make it easy. Much depends on slope, type of coverup and wind wind wind. What I have found is that depending on the situation, allowing some "give" is better than really tight. "Warps" poly is clear, not opaque but seems to last longer.
http://www.farmtek.com/farm/supplies/cat1;ft1_hay_storage_tarps;ft1_hay_tarps.html
I use these heavy black/silver and get up to three years out of them. All kinds of sizes.
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
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Thnx for the link and your time.
Edwin
There's an old article in FHB (JLC?) describing a reno like that in which they kept the existing roof on for a long time. Look into that.
I gather that the ceiling below was never designed for live weight, so it will be completely independent from the second floor framing, except at the edges, where it supports a plate. Everywhere else, there’ll be a 1 1/2” gap between the two. Did I get that right?
If so, I'd at least get the new floor in before tearing off the roof. Tear off enough sheathing to get good access where the new rim joist will go. Put some supports under the ridge, and using 2x scraps as rafter cut-off guides, cut each rafter with a Sawzall, and slip a 2x block under it. Then drive in a 2x8 plate, dislodging all of the blocks.
Repeat this process with scraps of floor framing nailed into Tees and topped with 3/4” ply. 15”x15” Tees will let you re-use the scraps as solid blocking later. Then you can work your rim joists in, probably in short sections, with a few 6’-8’ “joists” lagged into them to keep the rims from rolling.
With two 6’ sections of rim in at each end, you can start slipping full-length joists in through the middle slot and install them. Make sure you’ve slipped all of your joists and at least most of the plywood into the attic before you install the last section of rim joist, which will close off your access.
At any point in this process, you can tarp off in a jiffy: right from the start, nail or screw down a blue tarp just under a course of shingles, and flash that joint by slipping tarpaper up under the next course, and down over the tarp. The tarp can be folded back over the ridge, ready to go. Rips or full sheets of lauan are light, and easy to screw down to provide a non-puddling roof substrate under the tarp, so that your roof will shed water exactly as it used to do.
Of course, if I’m bidding a job like this, I allow for some water damage. But I proceed with a plan that avoids it entirely.
Who needs the stress, when a few extra hours of work can avoid it entirely?
AitchKay
Most likely not the answer you want, But the more help you have the faster the rafter are in place, You might look around & get some extra help. Having a roof off is always a night mare, more than once I've seen heavy storms come thru, rip tarp off & cause serious damage. Usually the worst part is after the wall are framed before ridge is up, makes it a real headache to cover over.
Best of Luck
The article that comes to mind is one from FHB (also featured in one of their books). However, I will not be able to follow his system because 1. I can't use the ceiling joists for the floor, and will have to build a new deck on top, and 2. I will be cantilevering on the sides and back.
Actually, there will be a 3" gap between the two ceiling and flooring joists. I figure that I will be shimming and leveling the second plate on top of the first one.
Consequently, I think I won't be able to put in the new floor until I remove the roof.
Any suggestions?
Thnx.
Edited 5/7/2009 1:46 pm ET by djthx
dj
By my count your going to put up and take down the tarp 8 times not including getting caught by unexpected showers.
Tarping over walls with no ceiling joist will really be fun, if thats when the rain comes.
What we have been doing for a long time now, is as follows;
for your house go buy two 30x50 tarps at menards, you can get an up grade over the 'blue' ones that have an extra coating for some extra money.
tear off the existing rafters
block between every other ceiling joist, flush with outside of top plate and add two 5-1/2" studs in the unblocked joist space.
plate down the center above the bearing wall, and block and plate the 22' side.
then unfold both tarps out in the yard, put one on top of the other and roll it up so you have a 30 foot long tube.
haul it up on the ceiling joist, center the tube on your 22' end and nail it to the 22' new plate, start rolling toward the other end. When you get out 17 or 18 feet stretch it tight on the blocked joist bay , let it sag in the unblocked joist bay and tack it down with roofing nails.(outer edge only) don't let it sag to much because if you do, you may need a 60' instead of a 50' tarp.
Then right away add a second plate down the center, and install a plate on top of your outside blocking (on the 40' sides). If you only got half the roof torn off just roll the tarp into the remaining attic space.
Finish double plating 22' side and the 40' side, mark your layout and start stocking your new 2x floor joist. You should plate the stair way opening under the tarp so you will have an easier time framing the stair opening in the new floor. It gos with out saying...don't cut the tarp til your dried in.
You will put the tarp down one time, and if it rains pack up your tools, go home, and rest easy. ( alot easier that tring to tarp the place with half the walls up and a 40MPH thunderstorm rushing toward you)
It won't leak and it can't blow off. Be careful with nails and splinters on top of the old joist and throw a fiberglass batt over anything that would cut or poke the tarp.
We have done this may times, protecting first floors with plaster coved ceilings, hardwood floors, and the clients who did not want to move out.
Regards Rich
dang, I almost think I understand you, but can you draw a section of that?http://www.tvwsolar.com
Now I wish I could give Brother Bill his great thrill
I would set him in chains at the top of the hill
Then send out for some pillars and Cecil B. DeMille
He could die happily ever after"
Snort
I was going to try to post some pictures, but the scanner decided to take the day off.
I did a little sketch, I will try to post it.
Rich
Snort
I will try to attach the sketch to this post.
Interesting, thanks.http://www.tvwsolar.com
Now I wish I could give Brother Bill his great thrill
I would set him in chains at the top of the hill
Then send out for some pillars and Cecil B. DeMille
He could die happily ever after"
Re: tarp only once..
Wow, sounds like a great system, but I must be missing something...what keeps the
tarp from sagging and collecting water in the blocked joist bays if you only nail it at
the outside edges?
It does collect some water. Much of the water will drain in joist bays that don't have blocks. The rest evaporates and sometimes the wind will billow the tarp and move water from the blocked bays to the unblocked bays. We have also been known to use a leaf blower either under or on top of the tarp to move water.
We also leave some plywood loose so the plumbers can do their work from the top side.
We have also cut 'V' notches on the tops of the blocks, that helps some.
We have also thrown 1/4" osb over the joist (under the tarp) in areas that we think may need extra support.
All in all it seems like less work and better weather proofing,(especially for an old guy with a small crew) and so far I've not had to buy any ceilings, wood floors, or carpet when we use it.
We use two tarps with the coating, the bottom tarp helps support the top one and protects it from damage, while the top one can hold water.
Rich
You could prefab all the walls and have a crane/crew get the shell up in one day. I can post pictures of a 850 sf house that we did that way. When I headed home for the day at 4:30, they were putting the felt on.
22 x 40 is slightly bigger but is quite doable.
We didn't actually lay the second floor plywood because we had to leave it open for inspections. We just scattered the sheets around to walk on and set all the wall on 1x6 boards on the edge.
If I had to do it again, I'd probably run one sheet of ply on the front and back to set the walls on.
If interested, I'll dig up the pics but I'm sure I've posted them here somewhere already.
I think it was Brian who mentioned once that for these uplifts, he gets roof off and floor framed, then lays ice and water shield on the subfloor to hold water out from below, then builds on up with less concern for tarping
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I'm pretty sure it was EPDM, because I looked into his method right after he posted it since we had a second floor addition to do.We were able to fast-track the framing and felting so we didn't end up doing it (a 24'x40' rambler- easy framing) but I will consider it in the future.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I have done the ice & water on the subfloor 3 times on projects simular to the OPs. All 3 involved multiple dormers and cedar roofs, making the blitz attack on closing in pretty difficult. You still have to use some tarps at some tie in areas, but not having to f around with tarps covering up everything is priceless.
Thnx for your input Jim. Did you have to put in new floor joists for your project? Did you also use 1 x 6 boards for the gable end as well?
Can you please send/post the pictures, or let me know where I can locate them?
Edwin
I have done as jim said before and I have also worked on a crew where we tore it off one day, reframed the next. I believe the house was a 28,48. We had it truss ready the second day. Halled the trusses up by hand and laid them down and tarped the whole building. Would have worked well except for one Bozo throwing a cig on the tarp after it was up, leaked live a sieve!!!
Moral of the story, whatch out for the Bozo's!!!!!!!!!!!!
Thnx for your comments. Did you also have to frame a new deck? I figure gutting the roof can be done in a day, new floor in a day, new SIP walls in a day, etc. Still, the project is going to need rain protection at every stage until the house is closed in, regardless of how long it takes. And that's my reason for this thread.
Floor and all walls one day! 5guys>G<
Amazing!
what size crew do you intend to use ?
most tarp jobs are an exercise in futility.... a 20 x 40 tarp is an 800 sf sail, like the mainsail on a 200ft schooner
if you get lucky, and there is no rain, you will do fine, if you get unlucky, just rain, you will have leaks
if you get real unlucky and you get wind and lots of rain, you will have a wet first floor
if you really want to try to save the first floor against all conditions, you have to build a false roof over the project and use a shrink wrap
instead of wasting your time and money on tarp strategies , i'd hire more help and a framing sub and get it up fast..
work sunup to sundown, start with a good longrange forecast
once the roof is sheathed , the new synthetic underlayments can make you water proof for 6 monthsMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Getting hard to find good sound advice lately.
Where you been?
Golfing?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
been tarping a roofMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
a 20 x 40 tarp is an 800 sf sail, like the mainsail on a 200ft schooner
Nah; a 200-foot gaffer oughta have more like 1500 SF on the main. We had at least 800SF on the Pioneer's mains'l when I was sailing her outta South Street in NYC in the 70s. 1885 iron-hulled schooner built for hauling sand to founderies down on the Delaware. Turned museum sail-training vessel in the early '70s. 64 feet on deck; 102 feet overall from the tip of the jib-boom to the end of the 60-foot-long main boom (which overhung the yawl boat by a coupla feet).
Heavy Dacron sails; about like 3 pairs of double-leg Carhartts sewn together. Hauling up that sail took four medium-sized volunteers, or two husky deckhands on the main and me on the throat halliard. Had to sweat the last three feet up tailing the halliard around the pin, too, or I'd just haul myself skyward instead o' getting any more lift on the throat....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Aargh, Matey!AitchKay
Thnx for your advice Mike. Were you serious when you mentioned "shrink wrap"? If so, what type?
Read MIke Smiths reply and follow, you won't go wrong.
We did have to install the new joist. Like you, we raised them a couple of inches. I can't remember if we raised them 1 1/2" or 3".
Heres some small pics of that project. If you want any of them bigger, let me know.
Thnx for the pix Jim. Kudos on a great job at a remarkable pace! Can you please explain the reason for the floor joists w/ blocking (the ones that look like ladders on the lawn). Do you think you can post bigger (and more) pix?
Edited 5/8/2009 5:39 pm ET by djthx
Another option might be to install a post and beam structure through the existing roof (with minimal penetrations) and then put a new roof on top of that. Then demo the existing roof. Less efficient than some other techniques but more flexible in terms of time, weather and manpower.
Those "ladders" are actually the soffit framing. The house had vinyl siding and trim. We put the subframe on the walls before we fly them.
Those walls were framed the previous day.
I'll post the largest sizes I have.
I think djthx was referring to this picture:View Image
Even if he was not, I'm curious. Was there a cantilevered portion of the floor, or did you just install blocking for the floor sheathing?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
That blocking is a typical detail that we do on all rim joists. Code calls for that type of blocking or a doubled up rim joist. In this case, the end blocking created a stable landing platform for the 1 x 6 "shim". We later had to add blocking between the blocks to carry the edges of the floor underlayment.
I can think of a few better ways to deal with that underlayment issue but when viewed in the context of this particular operation, sometimes it's better to leave things simple and fast and work on the details after the roof is on.
Edit: that blocking wasn't pre-built out on the lawn.
Edited 5/10/2009 7:22 am ET by jimAKAblue
Hello Jim,
Thanks for taking out the time to post all of those invaluable pictures. And thanks for clearing up my questions about the joist blocking. Because of the smaller pictures, I wasn't able to distinguish - the joist from the 2x 4 soffit blocking.
Edited 5/10/2009 10:32 am ET by djthx
My pleasure.
That's interesting, I've rarely seen that done here. Typically the only time I see perpendicular blocking like that is when there is a cantilever section, whether it be over a brick veneer, fireplace bumpout, or bay window.I like your 1x6 shim under the walls. It doesn't take that long to sheathe the floor, but if you're racing against weather/time, that little bit could be a big help. Plus, I could see leaving the floor open for access for trades and inspection could be a big benefit as well.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Our main motivation was to leave the floor open for inspections. We could have laid that floor in about an hour with the four guys that were there, so that "extra" time wouldn't have been a deal breaker.
On that particular job, rain clouds rolled in from nowhere and almost rained us out. We got lucky.
We blocked all the ends like that on every house. With a nailgun, and done in the right order, and using the right techique, it only adds about five minutes per span.
Yeah, that "extra" hour before lunch doesn't seem like much, but 60 minutes takes on a whole new meaning when it's 4:00 and you have rain clouds looming on the horizon!
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I've got 14 more pics. I'll split them into the next three posts.
Five more
Final four pics.
Were you concerned about existing headers, footer size, or anything like that? Did you have to do any boogering to make those existing members work?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
We didn't do any engineering on the existing structure. We just assumed that the first floor would hold it all up and we were right.
Most of the homes in those neighborhoods have adequate foundations. The soils are clay and sometimes sand. Metro Detroit didn't have trouble with foundations unless there was a swamp running under the house.
The house is actually pretty small. I think the the total footage on that second story was 800-850. If something went haywire, we would have simply dug a new foundation or installed extra beefy headers, where needed, at additional cost of course!