Jump to content

Building Using Insulated Roof Panels.


Recommended Posts

to_dave007

I'm new to this site, and just read this thread for first time.

 

My Texan friend Lavoy (R.I.P) and I built single story houses in northern Cebu in late 2013 and early 2014 with Union Galvesteel roof.  Lavoy's was built about 5 months ahead of mine, and Lavoy's and I cooperated throughout design and construction, until his passing.  Roof is approximately 140 square meters (mine) and 160 square meters (Lavoy).  Used the same Union Galvesteel steel design, but without the bonded insulation, so installation was applied in sheets on top of the steel purlins at standard spacing.  If I can figure out how to provide some photo's I can try to show the roof.

 

I involved a mechanical engineer in design, and both Lavoy and I used same foreman to lead construction crew (really excellent guy by the way).

 

Lavoy's house had roof on, and was in direct path of the winds coming on shore from Yolanda.. which as you know were quite strong.  His roof came through with FLYING COLOURS with zero leakage and zero wind damage except by one falling 90 foot tree which just clipped one edge.  I weathered Yolanda in Cebu 100 meters from the ocean from inside a building with an L shaped concrete wall protecting from the wind, and fully open on the other two sides..  and let me tell you it scared the living shit outta me.  The wind was like nothing I could have imagined, and I saw one tree..  15 feet tall.. so not big.. simply snap it's 6" to 8" trunk like a match stick in one gust.  In my municipality alone there were more than 1000 power poles broken..  and an unimaginable number of trees.  

 

Since your roofing panels are different from mine, with the bonded insulation, I can't comment on the strength of the long spans.  However if Union Galvesteel vouches for the strength I would feel comfortable, as I did find them both knowledgeable and helpful when I went to their Consolacion (Cebu) factory.

 

I'm an engineer, but not a mechanical engineer, but as I look at your roof design the main "fear" that I would have relates to the strength of the structural steel.. the trusses..  you've used to hold up the centre beam.  I'm sure the centre beam itself is fine, but those front and back trusses look pretty "light" to me.  The back one seems light but might be "ok", simply because I assume you've anchored it in multiple places along the roof beam.  But that front beam would scare me, as it will place ALL the mechanical loads into the two locations where it mounts to concrete, one at either end, with no other ties to the concrete structure, and fairly limited bracing within the truss.  Looks to me like you are planning to have an overhang at the front of the houses, and that you want an unobstructed glass view, likely out over the water.  I fear that you front truss may be much weaker than you think.  If you look at the design of the building that gave you inspiration for your house, you can see that the front truss is artfully designed, but the key thing is that it's designed for a higher strength, and without such weak points. 

 

I can see that you are past that point in your construction, and that this comment may not be helpful coming at this time.  For that I'm sorry and I sincerely hope I'm wrong. Maybe I don't know enough about what materials you used for the trusses.

Edited by to_dave007
Link to post
Share on other sites
  • Replies 150
  • Created
  • Last Reply

Top Posters In This Topic

  • riklynbor

    69

  • Headshot

    13

  • Paul

    13

  • Hy H

    12

Top Posters In This Topic

Popular Posts

So tired but there is progress. Fresh pictures hot of the press. Almost half the roof panels are up. First impressions are good. Today in the sun roof hot to touch but beautiful and cool underneath.

I haven't been this excited about pictures since I found my dad's playboy magazine at 9 yrs old.thanks

I am still around. The 8 meter wide folding doors are installed and look magnificent. The whole house is to be proud of. Still building it as we save money. No I am not on the Dole and nobody is givi

Posted Images

riklynbor

The strength of the truss has been brought up before. Materials for the upper section of the truss is 50mm x 5mm angle iron and the base is 2 heavy-duty C channel welded face to face. The weight of these are quite substantial. During construction of the roof the truss did not sagg even 1mm. Please follow my calculations. The panels are about 50kg each making total weight of panels 1100kg. The steel center pole hidden in the double wall would take 50% of the weight leaving 25% for front and back truss. This is 275kg for the back and front truss. Then most of the weight of that is taken by the 2 outer support points due to the slope of the roof panels.. But say for this instance 50% that leaves about 140kg of downwards force in the centre of the front beam which is minimal. Even with 3 more people standing on the completed roof over the front truss there is no sagg.

Also The font of the house does not overlook the water the house is deep in the mountains and it overlooks a hill. As the crow flies the house is 7 klm from the sea. There are close up pictures of the truss in this blog. About the roof that gave me inspiration it has a much bigger span than our house.

 

Local  roofs here get a lot of damage due to the guage of roof steel used. You can roll it up like tin foil and wil tear in the wind. They use it because it is cheap. Yes Galvasteel recommended this thickness panel for my span using 0.4 guage steel both sides. The guage of steel used in my panels is 0.6 on top and 0.6 bottom. I have stood mid span with 2 other workers about 200kg the panels sagged a little but most roofs would with 200 kg.

 

Thanks for the concern though. Rik

 

PS my roof is by far stronger than local roofs here that I have seen and that were not affected by Yolanda.

Edited by riklynbor
  • Like 3
Link to post
Share on other sites
to_dave007

I see your point about the strength of the truss to carry the weight you have on it.  I was more concerned about the wind load coming from underneath in that front section .. if the wind tries to lift the roof off.  I saw some places where the wind bent up some trusses pretty good.  But you do seem to have built quite a bit of strength into that truss.

Link to post
Share on other sites
oztony

I see your point about the strength of the truss to carry the weight you have on it.  I was more concerned about the wind load coming from underneath in that front section .. if the wind tries to lift the roof off.  I saw some places where the wind bent up some trusses pretty good.  But you do seem to have built quite a bit of strength into that truss.

 

You know I have stayed away from comment on this from the beginning , Rik is doing such a fantastic job on this build and I can appreciate the aesthetics that he is trying to achieve .

I am not an engineer , I am a carpenter that can build a house from the ground up on my own , so I can also appreciate the comments from our engineers that we have here .

I believe structurally Rik has done well , but in saying that , I do think the comments in regard to uplift forces of the wind have merit , especially at the front overhang section of the roof .

Even though it may never occur , it is the 1 in a 100 situation that it might , given the aesthetic look to remain the same , a solution may be a couple of stay arms , painted the same colour as wherever they are mounted ,

they don't have to be permanently mounted for all to see , but could be mounted in a position against the gable , or on the underside of the roof (blending in with the right colour) and they could pivot out to or down to a fixing , the use of which only to be engaged when a force that warrants it is on the way . possibly somewhere midspan would do ,like on a 45 degree angle from somewhere on the gable to underside of roof , could possibly just be done with one inch round bar . If this was catered for before the gable was sheeted/clad you would be able to weld in a mounting plate in the right position to allow for it , and I don't think the look of what is being achieved would be compromised. I am not going to go into support / whatever where it is fixed to on the underside of roof panels , that goes without saying .

Righto , now fella's slap me down

Edited by oztony
Link to post
Share on other sites
riklynbor

Nahh not gona slap you down as I have thought of similar ideas myself. If the front does peel up from the wind it would only go as far as the front truss. Overhang is only 1800mm or 1.8 sheets at the center and 1 meter at the side. The 9th panel that reaches just over the front truss has been screwed to the truss along its full length through the 5mm angle bar. With the screws every second tile or less than 600 apart. The reason I have no eaves down the sides or rear of building it for precisely that the wind factor. If it does happen and the 2 front sheets get damaged that is not a big job to replace.

  • Like 3
Link to post
Share on other sites
riklynbor

Front view of the house not the most spectacular not like the rear view but I still like it

 

post-14249-0-18927700-1408936039_thumb.jpg

 

post-14249-0-25878000-1408936187_thumb.jpg

  • Like 2
Link to post
Share on other sites
riklynbor

If you use Google+ look me up under Rik Bor tell me who you are that you are from Living in Cebu and I will add you as friend for more pictures. Rik

Link to post
Share on other sites
Headshot

Pic 1 is of 5 watt LED light in webbed truss.

 

I have a sneaking suspicion that at some point you will wish that you installed double LED spots rather than LED recessed lights in the beam above your balcony. The spots have the advantage of being able to put a lot of light exactly where you want it.

 

Something like this...

 

post-6379-0-75950800-1408949491_thumb.jpg

Edited by Headshot
  • Like 1
Link to post
Share on other sites
riklynbor

There will be similar lights along the outside walls above the beams. But the lights in the beam are spring loaded and if desired you can put offset rings behind them giving a certain amount of control. But I am hoping the light wil reflect off the ceiling giving a even distribution of light. We wil find out when the time comes.

 

 

 

I have a sneaking suspicion that at some point you will wish that you installed double LED spots rather than LED recessed lights in the beam above your balcony. The spots have the advantage of being able to put a lot of light exactly where you want it.

 

Something like this...

 

attachicon.gifSpot Light.jpg

  • Like 2
Link to post
Share on other sites
to_dave007

Not sure if you already bought your electrical panel.. or what size you need.

 

When I built mine I wanted a panel sized bigger than what I could find easily, plus I wanted a ground rod that I could not find locally.  Electrician kept telling me we could get the ground rod at Cebeco, the local utility, but they were always out of stock.  So.. end result was that I needed to go shopping for the panel and the ground rod, and could NOT find what I needed in any of the normal spots.

 

Then.. one Pinoy customer at one of the hardware places I was trying directed me to several electrical stores near the Carbon Market in Cebu City.  Racking my brain trying to remember name of the stores.. I think SureBright Electric was one of them.. anyway there are about 4 of them all within about a 2 or 3 block area, and if you have hard to find electrical requirements these are the place to go.  Plaridel Street . I think..  If you ever need this then PM me first and I'll get better directions. 

Link to post
Share on other sites
riklynbor

Not sure if you already bought your electrical panel.. or what size you need.

 

When I built mine I wanted a panel sized bigger than what I could find easily, plus I wanted a ground rod that I could not find locally.  Electrician kept telling me we could get the ground rod at Cebeco, the local utility, but they were always out of stock.  So.. end result was that I needed to go shopping for the panel and the ground rod, and could NOT find what I needed in any of the normal spots.

 

Then.. one Pinoy customer at one of the hardware places I was trying directed me to several electrical stores near the Carbon Market in Cebu City.  Racking my brain trying to remember name of the stores.. I think SureBright Electric was one of them.. anyway there are about 4 of them all within about a 2 or 3 block area, and if you have hard to find electrical requirements these are the place to go.  Plaridel Street . I think..  If you ever need this then PM me first and I'll get better directions. 

 

Thanks for the info buddy but already installed. I drew up my own electrical plan with the approval of a local Seleco contractor. I have three panels one for each floor.

A 10 switch board on the first floor with a main 100 amp breaker then I run number 6 cable to each floor to separate 6 switch panels. Reason being that if there is a problem on one of the floors the rest of the house is fine and no need to go all the way down stairs to reset the breakers.

 

post-14249-0-60439600-1408961532_thumb.jpg

  • Like 2
Link to post
Share on other sites
towboat72

im getting ready to buy roofing forthe house im building.can you tell me if what you used is available in cebu and if so where at  

 

 thanks iv enjoyed you project it has been VERY informative

Link to post
Share on other sites
riklynbor

It is available anywhere in Philippines but it is only made in manila and needs to be shipped to where it is required.

I  ordered mine from Union Galvasteel in Cebu who in turn ordered it from the factory in manila who shipped it to me. Be aware it takes about two months for manufacture and delivery so order in plenty time.

im getting ready to buy roofing forthe house im building.can you tell me if what you used is available in cebu and if so where at  

 

 thanks iv enjoyed you project it has been VERY informative

  • Like 1
Link to post
Share on other sites
towboat72

It is available anywhere in Philippines but it is only made in manila and needs to be shipped to where it is required.

I  ordered mine from Union Galvasteel in Cebu who in turn ordered it from the factory in manila who shipped it to me. Be aware it takes about two months for manufacture and delivery so order in plenty time.

thats what i needed to know,again thank you

Link to post
Share on other sites
to_dave007

In Cebu, Union Galvesteel is located in Consolacion (or was it Liloan - not sure where boundary is.. I think on Consolacion side though) right on the North Coastal Road, on the ocean side, about 1/2 way from the old Cansaga Bay bridge to the spot where the north coastal road joins back up with the main Cebu North Road in Liloan. It's a big place. Looks like a factory. They open at 8am. When you get there go through security and you'll be given a priority number (e.g. now serving number 8.. at 8:15 I was # 2 in the line) and sent into the main office. Most of the people arriving there are contractors who know what they want.. and some owners. Walls have lots of samples of the various products. They'll bring out a specialist.. and for those of you who've shopped at places like Wilcon you are in for a pleasant surprise.. as these specialists really do know their stuff. Even the receptionist in that room is very knowledgeable. If you talk to her about the stuff she might surprise you.

 

riklynbor is right, I think, that the Galvesteel he's using (i.e. bonded with insulation) is made at main Manila factory and was shipped to him from Manila. The Galvesteel I used was "made" in Manila as well, but is shipped to Cebu in a big roll.. and is unrolled and "formed" and cut to length there in that Consolacion factory. The Consolacion factory does not have the ability to apply the colour to the metal.. or fasten the insulation riklynbor used.. but it can do most "cut to order" on more standard jobs (i.e. without the insulation). I think Consolacion maintains inventory of all the standard colours.

 

If you do go to their office, it's a good idea to take your roof drawings with you, and the drawings of the roof beams and trusses. Photo's if you have them. If you ever place an order with Union Galvesteel they will need your full drawings, and measurements, because they cut all the roof pieces to order. which means a lot less waste for you.

 

Which reminds me.. riklynbor how did they do with the lengths of your pieces.. did you need to trim them? or was length good already?

Edited by to_dave007
  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use, Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue..